Devoir de Philosophie

Africa - Geography.

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Africa - Geography. I INTRODUCTION Africa, second largest of Earth's seven continents, covering 23 percent of the world's total land area and containing 13 percent of the world's population. Africa straddles the equator and most of its area lies within the tropics. It is bounded by the Atlantic Ocean on the west, the Indian Ocean and Red Sea on the east, and the Mediterranean Sea on the north. In the northeastern corner of the continent, Africa is connected with Asia by the Sinai Peninsula. Africa is a land of great diversity. If you were to trek across the continent, you would pass through lush, green forests and wander vast, grassy plains. You would cross barren deserts, climb tall mountains, and ford some of the mightiest rivers on Earth. You would meet diverse people with a wide range of cultures and backgrounds and hear hundreds of different languages. You would pass through small villages where daily life remains largely the same as it has been for hundreds of years, as well as sprawling cities with skyscrapers, modern economies, and a mix of international cultural influences. Africa is the birthplace of the human race. Here, early humans evolved from apes between 8 million and 5 million years ago. Modern human beings evolved between 130,000 and 90,000 years ago, and subsequently spread out of Africa. Ancient Egypt, one of the world's first great civilizations, arose in northeastern Africa more than 5,000 years ago. Over time many other cultures and states rose and fell in Africa, and by 500 years ago there were prosperous cities, markets, and centers of learning scattered across the continent. During the last 500 years, however, Africa became increasingly dominated by European traders and colonizers. European traders sent millions of Africans to work as slaves on colonial plantations in North America, South America, and the Caribbean. Europeans also sought Africa's wealth of raw materials to fuel their industries. In the late 19th century, European powers seized and colonized virtually all of Africa. Through slow reform or violent struggle, most of Africa won independence in the 1950s and 1960s. Independent Africa inherited from colonization a weak position in the global economy, underdeveloped communication and transportation systems, and arbitrarily drawn national boundaries. The citizens of these new nations generally had little in terms of history or culture to bind them together. There are 53 different African countries, including the 47 nations of the mainland and the 6 surrounding island nations. The continent is commonly divided along the lines of the Sahara, the world's largest desert, which cuts a huge swath through the northern half of the continent. The countries north of the Sahara make up the region of North Africa, while the region south of the desert is known as sub-Saharan Africa. Sub-Saharan Africa is sometimes referred to as "Black Africa," but this designation is not very helpful, given the ethnic diversity of the entire continent. North Africa consists of the countries of Algeria, Egypt, Libya, Morocco, Sudan, and Tunisia. Sub-Saharan Africa is generally subdivided into the regions of West Africa, East Africa, Central Africa, and southern Africa. For the purposes of this article, West Africa consists of Benin, Burkina Faso, Cameroon, Chad, Côte d'Ivoire, Ghana, Guinea, Guinea-Bissau, Liberia, Mali, Mauritania, Niger, Nigeria, Senegal, Sierra Leone, The Gambia, and Togo. East Africa consists of Burundi, Djibouti, Eritrea, Ethiopia, Kenya, Malawi, Mozambique, Rwanda, Somalia, Tanzania, and Uganda. Central Africa consists of Angola, Central African Republic, Democratic Republic of the Congo, Equatorial Guinea, Gabon, Republic of the Congo, and Zambia. Southern Africa consists of Botswana, Lesotho, Namibia, South Africa, Swaziland, and Zimbabwe. The island nations located off the coast of Africa are Cape Verde and São Tomé and Príncipe in the Atlantic Ocean; and Comoros, Madagascar, Mauritius, and Seychelles in the Indian Ocean. II NATURAL ENVIRONMENT The great diversity of the African environment makes it difficult to generalize about the continent. While much of the continent consists of vast plains with little relief, there are also towering volcanic peaks and the largest rift valley system in the world. The climate ranges from the year-round heat and humidity of equatorial regions to the dryness of the world's largest desert to mountaintop conditions cold enough to support glaciers. It contains regions of biological significance due to their biodiversity and huge numbers of species found nowhere else. The African environment has long been mistakenly seen as hostile, foreboding, and tragically in decline. Popular descriptions of Africa such as "the dark continent," images of untamed wilderness in nature publications, and sensationalized press coverage of disasters such as droughts and famines have shaped these perceptions of Africa. Geographers' accounts of Africa used to attribute the underdevelopment of the continent to its unfavorable environment--its oppressive climate, infertile soil, polluted water, and exotic diseases. These days have begun to wane. Increased scientific research on the African environment has done much to dispel old misconceptions and to provide insights into the physical processes that give shape to the landscape. The relationship of African societies to the environment is also much better understood. Yet much remains to be done before this huge and complex continent is well known and appreciated, especially by the general public. A The African Landscape The African continent covers 30 million sq km (12 million sq mi), including its adjacent islands. It stretches 8,000 km (5,000 mi) from its northernmost point, Ra's al Abya? in Tunisia, to its southernmost tip, Cape Agulhas in South Africa. The maximum width of the continent, measured from the tip of Cap Vert in Senegal, in the west, to Raas Xaafuun (Ras Hafun) in Somalia, in the east, is 7,500 km (4,700 mi). The highest point on the continent is the perpetually snowcapped Kilimanjaro (5,895 m/19,341 ft) in Tanzania, and the lowest is Lake 'Asal (153 m/502 ft below sea level) in Djibouti. Africa is surrounded by oceans and seas: the Atlantic Ocean on the west, the Indian Ocean on the east, the Red Sea on the northeast, and the Mediterranean Sea on the north. Madagascar, the fourth largest island in the world, lies off the southeastern coast. Other offshore islands include the Madeira Islands, Canary Islands, Cape Verde Islands, São Tomé, Príncipe, and Bioko, off the western coast; and the Comoros Islands, Seychelles, Mascarene Islands, and Socotra, off the eastern coast. A1 Surface Features Africa generally consists of a series of flat and gently undulating plateaus occurring at different levels, broken by a few mountainous areas and by the rift valleys of East Africa. With a mean elevation of approximately 650 m (2,100 ft) above sea level, Africa is high compared to other continents. The southern and eastern section of the continent, often called High Africa, consists primarily of a high plateau with elevations between 1,000 and 2,000 m (3,000 and 7,000 ft) above sea level. Northern and western Africa, widely known as Low Africa, has much lower mean elevations. Most of the continent's surface has been warped into a series of large, saucer-like basins separated by highlands. The major basins of Africa are El Djouf, now occupied by the Niger River Basin in West Africa; the Chad Basin, surrounding Lake Chad in west central Africa; the Sudan (or Nile River) Basin in northeast Africa; the Congo River Basin of Central Africa; and the Kalahari (or Okavango) Basin of southern Africa. A1a Highlands The highest elevations in Africa are found in the various ranges of East Africa. After Kilimanjaro, the next highest peaks are Mount Kenya (5,199 m/17,057 ft), north of Kilimanjaro in central Kenya; Margherita Peak (5,109 m/ 16,762 ft) in the Ruwenzori Range on the border between Uganda and the Democratic Republic of the Congo (DRC); Ras Dashen (4,620 m/ 15,157 ft) in the Ethiopian Highlands of northern Ethiopia; Mount Meru (4,565 m/ 14,977 ft), close to Kilimanjaro in Tanzania; and Mount Elgon (4,321 m/ 14,177 ft) on the Uganda-Kenya border. Africa's other major mountainous regions occur at the northern and southern fringes of the continent. The Atlas Mountains, a system of high ranges, extend for 2,200 km (1,400 mi) across Morocco, Algeria, and Tunisia, roughly parallel to the northern coast. These ranges enclose a number of broad inland basins and plateaus. In the west, the High (or Grand) Atlas contains Toubkal (4,165 m/ 13,665 ft), the highest peak of the system. Toward the east, the Atlas consists of two parallel ranges: the Tell Atlas to the north and the Saharan Atlas to the south. In southern Africa, the U-shaped Great Escarpment extends 5,000 km (3,000 mi) along the coast from Angola to Mozambique (an escarpment is a ridge that is steep on one side and slopes down gently on the other). The Drakensberg Mountains form the most pronounced relief of the Great Escarpment, rising to 3,482 m (11,424 ft) at Thabana Ntlenyana in Lesotho. Cameroon Mountain is the highest peak in West Africa at 4,095 m (13,435 ft). To the north, isolated highlands occur in the desert land of the Sahara, including the Ahaggar Mountains in southern Algeria and the Tibesti in northern Chad. A1b Great Rift Valley The Great Rift Valley is one of the most distinctive features of African topography. Formed where Earth's crust is being pulled apart by the action of convection currents beneath the surface, rift valleys are long, deep valleys bounded by parallel faults, or fractures, in Earth's crust. The Great Rift Valley system begins in Syria, in the Middle East, and extends southward, down the length of the Red Sea. It enters Africa at the Afar Depression on the coast of Eritrea and Djibouti, and winds some 5,600 km (3,500 mi) to the coast of southern Mozambique. In its middle section, it breaks into two major branches, the Eastern Rift Valley and the Western Rift Valley. The rift valley is flanked by towering escarpments of up to 1,000 m (3,000 ft) in southern Ethiopia, 1,500 m (4,900 ft) along the Eastern Rift in central Kenya, and 1,300 m (4,300 ft) in the northern part of the Western Rift, along the DRC's border with Uganda, Rwanda, and Burundi. The southern extremities of the rift system are much less spectacular in size and appearance. For more information, see the Faulting and Rift Valleys section of this article. Several major lakes, typically long and narrow, are located on the floors of the Western and Eastern rift valleys. The Western Rift contains Lake Albert, Lake Edward, and Lake Kivu to the north, Lake Tanganyika in the middle, and Lake Malawi (Lake Nyasa) to the south. The lakes of the Eastern Rift tend to be smaller and include Lake Naivasha, Lake Natron, and the southern part of Lake Turkana. A1c Deserts The Sahara is the world's largest desert. It stretches from the Atlantic Ocean to the Red Sea, and from the Mediterranean Sea and Atlas Mountains southward for 2,000 km (1,000 mi) until it merges imperceptibly into the semidesert Sahel region. Most of the desert consists of extensive plains covered with loose gravel and boulders, called reg. The rest of the desert is made up of areas of shifting sand dunes, called erg, interspersed with stretches of bare, rocky areas called hamada. The Namib and Kalahari deserts of southern Africa are much smaller than the Sahara. The Namib Desert stretches along the Atlantic coast for 1,500 km (930 mi) from southern Angola along the entire length of Namibia, and into western South Africa. The nearby Kalahari Desert, in Botswana, Namibia, and South Africa, is a semiarid region in the center of the Kalahari Basin. A1d Coastline Generally, Africa's coastline is very even, with few good natural harbors. The coastal plain is narrow around much of the continent, particularly in the south and east. Major escarpments run parallel to the coast in several areas. Most of the Red Sea and Indian Ocean coastline is fringed by coral reefs, which are an obstacle to ships. On the Atlantic coast, waters are generally too cold for coral development. Africa's best natural harbors are found in the many deep coastal inlets between Senegal and Liberia, especially at the mouths of rivers. Lagoon coasts, with a coastal barrier beach backed by lagoons, are common between Liberia and Nigeria. A2 Formation of Africa Scientists use the theory of plate tectonics to explain the formation of Africa and the other continents. According to this theory, the crust of Earth's surface consists of a collection of 14 rigid plates floating on an underlying mantle. These plates are in constant motion--moving apart, colliding, and thrusting beneath one another. Africa sits at the center of the African Plate, one of the largest of Earth's plates. For much of Earth's history, the land made up one vast supercontinent known as Pangaea. About 220 million years ago, tectonic activity broke Pangaea apart into the supercontinents of Gondwanaland and Laurasia. Gondwanaland subsequently broke apart as well: First Antarctica, Australia, Madagascar, and the Indian subcontinent broke away, followed by South America. Africa, at the core of Gondwanaland, assumed roughly its present-day shape about 15 million years ago when the formation of the Red Sea split off the Arabian Peninsula. A3 Geological Structure The geological structure of Africa is very complex, reflecting many stages and types of development over a period of 3.5 billion years. Most of the continent consists of rock dating from the Precambrian Period (more than 570 million years ago). These rocks are either igneous rocks such as granite or metamorphic rocks such as schist, gneiss, and quartzite. These ancient rocks--along with some slightly younger sedimentary rocks such as sandstone and limestone--make up what is called the basement complex of the African continent. In much of the continent, younger deposits of igneous and sedimentary rock were laid down on top of the basement complex. The largest of the sedimentary deposits formed in northern and western Africa during the Paleozoic Era (between 570 million and 240 million years ago). Later in the Paleozoic, sediments were deposited in parts of present-day South Africa. In the Mesozoic Era (between 240 million and 65 million years ago) this area was also covered with igneous basalt from major lava flows. Sedimentary limestone was deposited during the Mesozoic on Africa's northern edge. More recent sedimentary deposits dating from the Cenozoic Era (from 65 million years ago to the present) occupy the bottoms of the continent's large, shallow interior basins and some coastal areas. A4 Geological Evolution Africa contains three major cratons, or areas of basement-complex rock that have been geologically stable for hundreds of millions of years. The Kalahari craton is located in southern Africa, the Congo craton is in Central Africa, and the northwest African craton, forming the core of West Africa, is centered in the western Sahara. Areas between the cratons contain somewhat younger rocks. These areas have undergone more extensive and continuing geological change since the late Precambrian Period, caused by processes such as faulting, volcanism, folding, and crustal displacement. A4a Faulting and Rift Valleys Faulting, meaning the cracking of the Earth's crust, continues to break apart the African continent. Faults occur between two parts of the crust that are moving slowly and sporadically in relation to each other--either moving away from each other or sliding up, down, or side to side. When two pieces of land are being pulled apart, numerous parallel faults develop between them as the edges cleave off and are displaced downward. The resulting formation is known as a rift valley, with a steadily lowering valley floor bounded by steep cliffs known as rift scarps. The Great Rift Valley system of East Africa traces sets of parallel faults in the African Plate that run from the Afar Depression in Eritrea and Djibouti to southern Mozambique. Millions of years from now, as the Great Rift Valley continues to widen and deepen, East Africa will likely split off from the rest of the continent. The Great Rift Valley is not uniform: Different segments are distinct in appearance and are affected by different geological activities. The triangular Afar Depression (also known as the Afar Triangle), a very low area fringed by rift scarps, is geologically unstable. The depression is widening and deepening by several centimeters per year, with accompanying volcanic activity and frequent earthquakes. In the part of the Western Rift where Lake Tanganyika is located, there has been a vertical displacement (the distance between corresponding rock strata in the land above the rift and in the lowering rift valley bottom below) of up to 6,000 m (20,000 ft). Some parts of the rift system (for example, the northern part of the Western Rift) are associated with very extensive volcanic activity, while in other areas (such as the Lake Tanganyika sector), volcanic activity is absent. Rift systems occur elsewhere in Africa, most notably in the valley of the Benue and lower Niger rivers in Nigeria. Also in West Africa, volcanic activity and tectonic movement occurs along a major fault line that extends inland from the offshore island of Bioko through Cameroon Mountain to beyond Lake Chad. This line has been interpreted as the early stage of a rift system that could eventually result in the separation of West Africa. A4b Volcanism Volcanism has contributed significantly to the shaping of the African continent since ancient Precambrian times. Considerable volcanic activity accompanied the breakup of Gondwanaland, notably creating extensive lava deposits in southern Africa and covering the Ethiopian Plateau with massive deposits of basalt. Elsewhere in Africa, volcanism is associated with hot spots, areas located directly above focused plumes of magma rising from the Earth's interior. The Tibesti and Ahaggar mountain ranges of the central Sahara, both volcanically active regions, sit over hot spots. Other hot spots lie under Cameroon Mountain, the Western Rift Valley, and several offshore locations such as Comoros and Réunion in the Indian Ocean and Ascension and Saint Helena in the South Atlantic Ocean. The most spectacular products of volcanism are several major peaks associated with the Great Rift Valley system in East Africa. These now-dormant peaks include Kilimanjaro, Mount Kenya, Mount Meru, and Mount Elgon. In contrast, Nyiragongo and Nyamulagira in the Virunga Mountains--along the border between Rwanda and the DRC--and Cameroon Mountain are active volcanoes. Africa's extensive lava plateaus, though less spectacular than the volcanic peaks, are nonetheless important to the continent's development. The weathering of these volcanic deposits has provided some of Africa's most productive soils. Rwanda and Burundi are examples of regions of volcanic origin that support very productive agriculture and high population densities. A4c Folding Differences in pressure in the Earth's crust cause it to buckle upwards, or fold. Folded mountains are less prominent in Africa than in other continents, a reflection of the geological stability of its basement-complex rocks. The Atlas Mountains in northwestern Africa and the Cape ranges--including the Swartberg and Langeberg mountain ranges--in South Africa are the only examples of folded mountains on the continent. A4d Crustal Warping and Uplift Over the last 500 million years, Africa has experienced many sequences of surface warping. In this process, crustal pressure bends the Earth's surface without creating folds or faults. Downwarping created the continent's major basins, while upwarping produced upland regions such as the Guinea Highlands and Ethiopian Highlands. These uplands fringe the basins, and divide them from one another. For example, the Ahaggar, Tibesti, Ennedi, and Mambila mountains, together with the Jos Plateau, surround the Chad Basin. Much of the African continent lifted up after it separated from the other continents due to isostatic adjustment (the tendency for Earth's crust to seek gravitational equilibrium). This uplift took place over a prolonged period, and was especially significant in the south, where it gave rise to the Great Escarpment along the fringe of the continent. In East Africa, the tectonic processes that created the rift valleys simultaneously created upwarped areas and uplifted mountain ranges, the largest being the Ruwenzori Range along the Uganda-DRC border. A5 Weathering and Erosion The surface of Africa, like all continents, is affected by weathering and erosion. Weathering refers to the processes of physical disintegration and chemical decomposition of solid rock materials at or near the Earth's surface, while erosion refers to the removal of weathered rock and soil material by natural processes such as running water, glaciers, waves, and wind. The general flatness of much of the African landscape is the result of deep chemical weathering of bedrock, together with prolonged erosion that has smoothed the surface over many millions of years. A5a Processes in Humid Tropical Regions The year-round rainfall and high temperatures that prevail in the humid tropics are ideal for chemical weathering. Chemical weathering involves the decay and disintegration of rock through chemical alteration of the minerals that make up the rock. In tropical forest environments, water filters through decaying vegetable matter on the ground and becomes acidic, helping it break down rock. Such is the effectiveness of chemical weathering that it is common to find 15 m (50 ft) or more of weathered material overlying solid rock in the tropical environments of Africa. Chemical weathering is important, but somewhat less effective, in savanna regions where rainfall is seasonal. As weathering forms soil in the humid tropics, iron and aluminum oxides filter downward, often resulting in a well-defined, cementlike layer of ferricrete or plinthite meters below the Earth's surface. When overlying sediments are eroded away, these layers form a rock-hard crust. These crusts--typically 1 to 10 m (3 to 30 ft) thick--form broad pavements, ledges, and flat cap rocks on mesas. Chemical weathering in the humid tropics and moister savannas creates isolated, domed rock outcroppings called inselbergs. Inselbergs are made of hard masses of crystalline rock that resist chemical weathering. When surrounding, weathered materials have been eroded away, the inselberg is exposed. The typical domed shape of many inselbergs is created through the successive peeling away (or exfoliation) of surface layers of rock. A5b Processes in Arid Regions In deserts, wind erodes and scours the landscape, creating weirdly shaped pinnacles, grooves, and canyons, both in lowland areas and in upland massifs such as the Tibesti and Ahaggar in the Sahara. Sediments carried from rock and gravel desert areas help to build ergs (stretches of sand dunes), including the immense Grand Erg Oriental that covers almost 200,000 sq km (80,000 sq mi). Ergs contain many types of dunes: crescent-shaped barchans, linear seif dunes up to 80 km (50 mi) long, and massive sand ridges known as draas. The shape and orientation of dunes in a particular area reflects several factors such as local wind patterns and variations in the amount of sand. Some ergs have several subregions in which dunes have different orientations. Past and present water action also affects the formation of desert landscapes. In the Namib Desert in southern Africa, salt, fog, and dew carried from the ocean contribute to weathering processes. A5c Glaciation Although Africa is now generally warm and tropical, glaciation played a significant role in the continent's development millions of years ago during the ice ages. When it was still a part of Gondwanaland, areas of Africa were covered in massive continental glaciers. They left behind deep deposits of tillite (rock formed from sediments deposited by glaciers) in southern Africa. Other tillite deposits are found in the Congo River Basin and in the northwestern Sahara. Glaciers are still found at the summits of some of Africa's highest peaks, including Mount Kenya and Kilimanjaro. These glaciers are all above 4,500 m (14,800 ft) today, but extended as low as 3,000 m (10,000 ft) during the most recent ice age. A5d Coastal Processes Coastal deposition (accumulation of sediment) occurs along much of the African coastline, particularly along the Mediterranean coast, along the Atlantic coast from Liberia to South Africa, and along the Indian Ocean coast of South Africa and southern Mozambique. Where there are strong winds parallel to the coast, waves and currents move sand along the coastline, in the process creating large sand spits and blocking harbors. At the mouths of the Niger and Nile rivers, large fan-shaped deltas have been created through the deposition of vast amounts of sediment carried downstream by these rivers. Few good harbors are found in areas where there are high levels of coastal deposition. A6 Economic Geology Africa is rich in mineral resources, particularly in the south. In South Africa, in the Witwatersrand region and the province of Free State, gold is extracted from rich reefs. These reefs consist of layers of old metamorphosed sediments that have been tilted upwards. The same formations also include several other minerals, such as copper, platinum, chromium, iron ore, and coal. Some mineral deposits were created when magma poured into older geological formations and cooled slowly, allowing the minerals to concentrate. This process produced the rich chromium deposits of the Great Dyke, a 520-km-long (320-mi-long) ridge bisecting Zimbabwe from northeast to southwest. A similar process produced diamond-bearing kimberlite deposits in countries such as the DRC, Botswana, South Africa, and Angola. Elsewhere--including Sierra Leone and other parts of the DRC--old streambeds contain diamonds that have been washed downstream. Guinea has large reserves of bauxite, the commercial source of aluminum. Here, processes of chemical weathering and leaching formed deposits with very high concentrations of aluminum oxide. Several of Africa's major sources of iron ore were similarly created as residual deposits associated with chemical weathering. Africa has significant reserves of petroleum and natural gas, concentrated in two main areas. One is in North Africa, especially in Libya and Algeria, where deposits are found in sedimentary basins south and east of the Atlas Mountains. The other major area of production is along the Atlantic coast between Côte d'Ivoire and Angola, where wells are situated both onshore and offshore. This region's most important center of production is the Niger River Delta. The central Nile Valley in southern Sudan is emerging as a new center of petroleum production, the first significant one in the African interior. B Rivers, Lakes, and Wetlands The water systems of Africa are extremely diverse, a reflection of the continent's great range of climate and physical geography. These systems vary from region to region, and from season to season and year to year as well. B1 Major River Systems Africa has several of the world's greatest rivers. The Congo, which alone accounts for some 38 percent of the continent's discharge into the ocean, drains an area of more than 4.1 million sq km (1.6 million sq mi), ranking second only to South America's Amazon River in terms of discharge and size of drainage basin. The Nile, which extends for 6,695 km (4,160 mi), is the world's longest river; it occupies the fourth largest drainage basin. Other important rivers include the Niger in West Africa and the Zambezi in southern Africa. The seasonal occurrence of rainfall in most of Africa often results in highly variable river flows. A river may have virtually no discharge in the late dry season followed by severe flooding in the rainy season or early dry season. Few of Africa's rivers have the relatively constant, year-round discharge of the Congo. Great seasonal fluctuations in discharge create challenges, both in limiting flood damage and in using rivers for irrigation, hydroelectric power generation, and navigation. Several major dams and reservoirs have been constructed, especially during the 1960s and 1970s, to address these problems. Today, dams regulate a greater proportion of total river discharge in Africa than on any other continent. Africa's river systems reflect the continent's unique physical geography. One-third of its area consists of inland basins, such as the Lake Chad and Kalahari (Okavango) basins, where rivers and streams never reach the ocean. Other major river systems, notably the Nile, Niger, and Congo rivers, have large inland deltas in midcourse, indicating that the upper portions of these rivers' drainage basins were also landlocked at some point. Several major rivers, including the Congo, Zambezi, and Orange, pass through narrow valleys and drop sharply as they cross escarpments fringing the continent. In its lower course, the Congo drops 270 m (886 ft) through a series of 30 rapids and waterfalls. River courses such as this provide ideal conditions for hydroelectric power generation. Africa has about 40 percent of the world's hydroelectric potential, but only a small proportion has been developed. B2 Lakes Africa's many lakes have diverse characteristics. They include deep lakes of tectonic origin (such as Lakes Malawi and Tanganyika in East Africa) and shallow lakes located at the center of drainage basins (including Lake Chad in West Africa). Lake Victoria, in East Africa, is the world's third largest lake by area, while Lake Tanganyika is the world's second deepest lake and third largest by volume of water. Africa's natural lakes have quite distinct ecologies: Lakes located close to each other often vary significantly in both abundance and types of fish and plant species. Most lakes contribute significantly to their regional economies, particularly as a source of fish. In drier regions, several lakes that lack natural outlets have high concentrations of mineral salts, or are actually saltpans that only contain water for part of the year. Some of these salt deposits are mined, among them the commercial soda works of Lake Magadi in Kenya and the centuries-old salt and natron extraction sites in pans in the Sahara. In addition to natural lakes, Africa has several large artificial lakes that were created by damming major rivers. These reservoirs include Lake Volta on the Volta River, Kainji Lake on the Niger, Lake Kariba on the Zambezi, and Lake Nasser on the Nile. Most of these projects were designed to generate hydroelectricity and, in some cases, to promote irrigated agriculture. A significant fishing industry has developed around some of the artificial lakes, especially Lake Volta. The new lakes flooded settlements and farmland--as well as vital floodplain ecosystems--in valley bottoms. The loss of annual floods due to damming has had a variety of ecological and economic impacts. Annual summer flooding of the Nile once deposited rich sediment along its banks, creating fertile farmland in Egypt for millennia. With the construction of the Asw?n High Dam in the 1960s, most silt was deposited in the newly created Lake Nasser, drastically reducing sedimentation and soil fertility downstream. B3 Wetlands Africa's freshwater wetlands come in several forms. They are often located in floodplains, low-lying areas adjacent to rivers that are subject to annual or periodic flooding. Freshwater marshes, such as the huge As Sudd in Sudan, are usually associated with riverside locations, and are dominated by herbaceous species such as papyrus. Swamp forests occur in floodplains or lakeside environments, most notably in the Middle Congo River Basin. This area contains about 8,000 sq km (3,000 sq mi) of permanently or seasonally flooded swamp forest. Wetland areas play a vital hydrological and ecological role in Africa. They trap and slow seasonal floods, dampening the magnitude of floods downstream and spreading out peak flows over several weeks or months. The delay and extension of flood peaks can facilitate downstream fishing and irrigation, especially in areas with an extended dry season. Wetlands also provide habitat for numerous species of animals and plants, many of them unique to these ecosystems. Wetlands near the edge of the Sahara provide vital staging grounds for migratory birds preparing to cross the desert. Wetlands also trap and hold silt carried by rivers, creating fertile alluvial soils that may be used to grow crops such as rice, cotton, and vegetables. However, agricultural development schemes, taking advantage of the presence of both fertile soil and water, pose a threat to many wetlands. Botswana's Okavango Delta is one of Africa's largest and most unique wetlands. The Okavango River, with its source in the highlands of Angola, forms a huge, swampy inland delta as it approaches the Kalahari Desert. During the annual floods, the swamp doubles in size. Although it has several outlets, virtually all of the water entering the Okavango Delta evaporates or is absorbed into the sandy subsurface. The Okavango supports a rich indigenous flora and fauna, and attracts huge numbers of migratory wildlife during the dry season. Like many others, this vital and sensitive wetland ecosystem is threatened by the growth of ranching and tourism, and by proposals to divert water for irrigation and other uses. C Climate Lying between latitudes 37° north and 35° south, Africa has virtually the same climatic zones in the Northern Hemisphere as in the Southern Hemisphere, and they are arranged symmetrically on either side of the equator. The zones are determined mainly by latitude, except in the east where highlands greatly modify the climate. Africa is the most tropical of the continents: Only its northern and southern extremes are directly influenced by mid-latitude westerly winds and are considered to have temperate climates. C1 Climatic Zones Most of Africa lies between the Tropic of Cancer (in the north) and the Tropic of Capricorn (in the south) and has high temperatures throughout the year. The amount, duration, and seasonal distribution of rainfall is therefore the most important factor differentiating its climates. Africa has six types of climatic zones: tropical wet, tropical summer rainfall, semiarid, arid, highland, and Mediterranean. C1a Tropical Wet Tropical wet climates, also called equatorial climates, occur close to the equator in West and Central Africa, and in eastern Madagascar. Rainfall is high, typically exceeding 1,500 mm (60 in) per year and 3,200 mm (130 in) in some places. Rainfall occurs in every month, and many areas experience especially rainy periods in the spring and in the fall. Temperatures remain high throughout the year, averaging more than 27°C (81°F) annually, and rarely falling below 21°C (70°F). C1b Tropical Summer Rainfall Tropical summer rainfall climates, also known as tropical savanna climates, occur north and south of the tropical wet zone, in much of West Africa and southern Africa and most of Madagascar. This climatic zone is marked by a well-defined dry season of three to eight months. Annual rainfall is usually between 500 and 1,500 mm (20 and 60 in), although limited areas have considerably more--for example, Freetown, Sierra Leone, averages 3,800 mm (150 in) per year. The tropical summer rainfall zone is a transitional zone between tropical wet and semiarid zones, so there is a progressive decline, moving poleward, in total rainfall and the duration of rainfall. Areas with a longer rainy season tend to have two rainy periods separated by a short dry spell, while areas with a shorter rainy season have a single rainy period. Temperature ranges in the tropical summer rainfall zone are slightly higher than in the tropical wet zone, and increase with distance from the equator. In the northern section of this zone, daily high temperatures average more than 30°C (90°F) over the course of the year. Temperatures in the southern and eastern sections of this zone tend to be cooler because of higher altitudes. C1c Semiarid and Arid Surrounding the tropical summer rainfall zone are areas of semiarid and then arid climates in north central Africa, east central Africa, and southern Africa. The semiarid, or hot steppe, zone has a short rainy season of up to three months with about 250 to 500 mm (10 to 20 in) of rain per year. Precipitation is unreliable and scarce, creating difficult conditions for plant growth. Temperatures vary in the semiarid zone, with average daily highs ranging from 25° to 36°C (77° to 97°F). Africa's arid desert regions receive little rainfall. Although classified as hot deserts, these regions have significant annual variations in temperature, and extreme fluctuations in temperature over the course of a day. In the Sahara, daytime summer temperatures can exceed 50°C (120°F), and winter nighttime temperatures can drop below freezing. C1d Highland and Mediterranean Tropical highland climates are common in much of East Africa. Temperatures in the highlands of Ethiopia and Kenya average 16° to 21°C (60° to 70°F), on average about 5 Celsius degrees (9 Fahrenheit degrees) cooler than the lower plateau areas of Kenya, Uganda, and Tanzania. In most parts of the world, higher elevations receive higher levels of precipitation, but the highlands of East Africa are an exception, experiencing rather low levels of rainfall. However, the highest mountains and the southeastern flank of the Ethiopian plateau receive greater precipitation on their windward slopes. The coastlands of the Cape region of South Africa and the North African coast from Morocco to Tunisia have Mediterranean climates. These areas have mild, rainy winters followed by a prolonged summer when conditions are warm and dry. They receive between 250 to 1,000 mm (10 to 40 in) of rainfall per year. C2 Major Climate Controls Several factors influence the climate of Africa, determining the continent's climatic regions, creating seasonal variations, and altering day-to-day weather. The most important climate control is related to atmospheric conditions and wind patterns; other major controls include topography, ocean currents, and clouds and other airborne material. C2a Seasonal Shifts of Winds, Atmospheric Pressure, and Air Masses Air masses moving over Africa have different characteristics depending on their areas of origin. Air originating over the tropical oceans, known as maritime tropical air, is warm, moist, and unstable. When this moisture-laden air is forced to rise and become cooler, condensation and precipitation often occur. Conversely, the hot, dry air that originates over the African continent (continental tropical air) is incapable of producing rain, even if it is forced to rise. Over most of Africa, air moves toward the equator. Northern Hemisphere winds from the northeast and Southern Hemisphere winds from the southeast converge at the intertropical convergence zone (ITCZ), a low-pressure zone centered on the equator. Air rises at the ITCZ, spreads out, and descends in the north and south, in subtropical high-pressure zones centered on the Tropic of Cancer and Tropic of Capricorn. After descending, the air flows outward, either poleward into temperate regions or back toward the equator. The ITCZ constantly shifts its position, moving north of the equator during the Northern Hemisphere's summer, and south of the equator during the Northern Hemisphere's winter. This shift brings about seasonal changes, notably in the tropical summer rainfall zone. During the summer season (July to September in the Northern Hemisphere and December to February in the Southern Hemisphere), moist maritime air is drawn in toward the ITCZ and produces rainfall when it is forced to rise. During the winter season (December to February in the Northern Hemisphere and July to September in the Southern Hemisphere), when the ITCZ is centered in the opposite hemisphere, dry conditions prevail due to the dominance of hot, dry winds coming from the subtropical high-pressure zone. These global, seasonal shifts in wind and pressure zones also bring about the seasonal changes that characterize the Mediterranean climates of Africa's northern and southern margins. These seasonal shifts have a comparatively minor impact on rainfall patterns in equatorial and desert regions. The mid-Sahara receives little rain, even in summer, because the ITCZ seldom advances that far north. On the other hand, equatorial regions lack a well-defined dry season because they continue to benefit from moist, maritime air throughout the year. Their position near the equator also ensures that temperatures remain uniformly high year-round. In contrast, Africa's desert regions experience significant temperature shifts seasonally, a reflection of their higher latitudes. Most of the continent receives moisture from air originating over the Atlantic Ocean. In eastern Africa, however, rainfall south of the equator comes from large tropical cyclones originating over the Indian Ocean during the Southern Hemisphere summer. Rainfall from these cyclones is particularly high in eastern Madagascar and the coastal mainland between South Africa and southern Tanzania. North of the ITCZ--centered during January over Tanzania--East Africa receives little rain because its air originates in dry, mainland Asia. C2b Altitude and Relief Africa, unlike other continents, has no great mountain ranges to impede or channel atmospheric circulation. However, altitude is an important influence on temperatures, notably in the high plateaus and highlands of southern and East Africa. Highland regions have lower temperatures throughout the year, compared to lower-elevation areas at the same latitude. Highlands also influence rainfall patterns: Moisture-laden air forced to rise over a mountain barrier produces more rainfall on the windward side than on the leeward side. C2c Ocean Currents Ocean currents affect the climate of the Atlantic Coast from South Africa to southern Angola, and from southern Morocco to Mauritania. The former is affected by the Benguela Current, while the latter is influenced by the Canaries Current. These cold ocean currents result in somewhat cooler temperatures, very low rainfall, and the frequent occurrence of fog near the coast. Elsewhere, an area of surprisingly low rainfall along the coast near Accra, Ghana, has been attributed to localized upwelling of cold water. C2d Clouds and Atmospheric Dust Clouds help to reduce daily temperature fluctuations by reflecting solar radiation away during the day, and by slowing the loss of heat at night. The lack of cloud cover in Africa's desert regions--and during the dry season in other climate regions--results in substantial day-to-night fluctuations of temperature. The Sahara is estimated to generate 300 million metric tons of airborne dust each year, 60 percent of the worldwide total. During the dry season wide areas south of the Sahara are affected by the harmattan, dust-laden winds originating in the desert. Typical episodes last for three to five days, with a dusty haze obliterating the Sun, lowering temperatures, and sometimes reducing visibility to a kilometer or less. The frequency and intensity of the harmattan varies; regions near the desert margins are often affected for 20 to 30 days per year. Dust originating over the Sahara also affects North Africa, southern Europe, and the Arabian Peninsula. The hot, dustladen winds that occur in North Africa between February and June are known collectively as sirocco, and locally by a variety of names (for example, khamsin in Egypt). C3 Climate Change The Sahel--the semidesert transition zone between the Sahara and the wetter tropical areas to the south--suffered from a severe drought from the late 1960s to the early 1980s. Scientists initially interpreted the drought as a new phenomenon in which reduced rainfall and inappropriate human use of the delicate environment were causing the desert to expand relentlessly. After greater research, however, many scientists now believe that the Sahelian drought is part of a long-standing cycle of change. The study of environmental change in the Sahel and in adjacent regions shows that the margins of the Sahara have shifted during the last 20,000 years. Some 18,000 years ago, glaciers covered much of northern Europe, and global climate zones shifted to the south. The boundary of the Sahara was far to the south of its present location, passing through southern Senegal and central Nigeria. Large areas of sand dunes in the Sahel demonstrate that the climate was formerly much drier than today. With the melting of the glaciers in Europe, the Sahara's southern margins shifted to the north as the climate became warmer and moister. About 9,000 years ago the desert had shifted far north of its current margin. Evidence of this shift includes sedimentary deposits indicating that Lake Chad was much larger than today, and that other large lakes existed in now-dry Saharan basins. Many vivid rock paintings in the central Sahara show savanna animals and people herding livestock more than 3,000 years ago. Since then, the climate has become progressively drier, the desert margin has moved south, and most of the lakes and wildlife have disappeared. Other climate changes in the Sahel have occurred over the past 500 years or so. These changes, especially in the amount of rainfall, have tended to be cyclical: a decade or two of poor rains, followed by moister conditions, followed in turn by drought. Evidence of these fluctuations comes from written and oral accounts of droughts and famines, archaeological evidence, and the analysis of fossils. In addition, meteorological records show cycles of increasing and decreasing rainfall just since the early 20th century. For example, the Sahelian drought was preceded by two decades of far-above average rainfall, and was followed by several years of average rainfall. Records also suggest an overall downward trend in average rainfall since 1900. Scientists have suggested that the clearing of vegetation and global warming may account for this apparent trend. They argue that the removal of vegetation causes higher surface temperatures, increased evaporation, and reduced rainfall. D Vegetation African vegetation zones are closely linked to climatic zones, with the same zones occurring both north and south of the equator in broadly similar patterns. As with climatic zones, differences in the amount and seasonal distribution of precipitation constitute the most important influence on the development of vegetation. Moving across the continent into drier and drier climates, the typical sequence of vegetation is from tropical moist forest to moist savanna, dry savanna, semidesert, and finally desert. D1 Tropical Moist Forest Tropical moist forest occurs in humid tropical areas, usually with 1,500 mm (60 in) or more of precipitation and a dry season (or seasons) of three to four months or less. West of the highlands of East Africa and centered in the basin of the Congo River is a great tropical moist forest extending some 600 km (400 mi) north of the equator and a similar distance south of the equator. On the west, the forest extends to the Atlantic coast in the Congo, Gabon, and Cameroon, and stretches in an interrupted belt along the West African coast to Sierra Leone. Tropical moist forest also occurs along the eastern side of Madagascar. Scientists recognize two major subtypes of tropical forest: tropical rain forest and tropical wetland forest. Tropical rain forests are characterized by a dense mass of evergreens, oil palms, and numerous species of tropical hardwood trees divided vertically into strata, or layers. The upper canopy of treetops forms a dense cover over the middle layer of treetops and the surface layer of shrubs, ferns, and mosses below. Rising above the canopy are scattered tall trees, known as emergents. In dense forest environments, the shrub layer tends to be quite sparse, except along streams, because the canopy limits the amount of light that penetrates to the forest floor. Tropical rain forests are extremely diverse in species; pure stands of a single tree species are rare. Tropical wetland forests include both freshwater and saltwater subtypes. Freshwater swamp forests cover large parts of the Middle Congo River Basin. Saltwater swamp forests occur in many areas between Senegal and Angola on the Atlantic coast and between South Africa and the Red Sea on the coast of East Africa. Mangrove species, with their characteristic tall, arched roots, are highly adapted to the fluctuating water levels and brackish water found in estuaries and other tidal environments. Mangrove forests are tangles of roots, tree trunks, and branches reaching 8 to 23 m (25 to 75 ft) high. Significant areas of mangrove forest have been lost in order to clear land for rice cultivation, particularly in West Africa. D2 Tropical Savanna Surrounding the central tropical forest zone on the north, east, and south is a zone of tropical savanna vegetation that covers up to 65 percent of the continent. The savannas have somewhat drier climates compared to the tropical forests. They typically receive 500 to 1,500 mm (20 to 60 in) of precipitation per year, and have a pronounced dry season, usually from three to eight months long. Moving poleward, savanna vegetation transitions from moist woodland savanna to dry woodland savanna. Moist woodland savanna occurs close to the tropical forest, where climates are wetter and the dry season is only three to four months. The characteristic vegetation is a mixture of tall grasses and closely spaced trees. Vegetation is especially dense along river courses, with trees lining the banks in gallery forests. Shrubs and grasses are also dense in areas where intensive cultivation and past use of fire to clear vegetation have led to the degradation of once forested lands. Shea trees occur widely; their tough outer bark is fire-resistant and their kernels are a source of oil for cooking and other uses. Dry woodland savanna, frequently called Sudan savanna, occurs where there is less precipitation and a prolonged dry season of about five to eight months. As precipitation declines, grass becomes shorter and sparser, and the tree cover less dense. The baobab is the largest tree; it is widely distributed and is valued for its inner bark (from which rope may be made) and its edible leaves and fruits. Other common trees are the silk cotton and locust bean, and various species from the acacia and fig (ficus) families. D3 Semidesert and Desert In the semidesert, or steppe, zone that lies between the dry woodland savanna and the desert, annual precipitation is between 250 and 500 mm (10 to 20 in). Rainfall is limited, localized, irregular, and often violent. Semidesert vegetation fringes the Sahara on the south (where this zone is referred to as the Sahel savanna), north (especially the southern slopes of the Atlas Mountains) and east (on the Red Sea coast). It also occurs in Somalia and northeastern Kenya, in the Karoo plateau regions of South Africa, and on the inland margin of the Namib Desert of Namibia and Angola. In addition, the Kalahari Desert is actually a semidesert region, despite its name. In many of these areas, vegetation occurs in strips running along contours in the land, where there has been an accumulation of moisture and soil. These vegetated strips are usually separated by wide barren areas. With increasing aridity, the drought-resistant properties of plants become crucial for their survival. Trees must be adapted to the prolonged dry period, with deep root systems, thick bark, small leaves that may be shed, and thorns to discourage animals from feeding on them. With still greater aridity, only grasses and desert shrubs survive. Semidesert vegetation is vulnerable to damage from fire, clearing for cultivation, and overgrazing. Desert vegetation occurs in the Sahara and Namib deserts, areas with less than 250 mm (10 in) of rainfall per year. Desert plant life must adapt to the harsh conditions of sparse, infrequent rainfall and extreme temperatures. The seeds of some species lay dormant for prolonged periods, until there is moisture to support their growth. Large areas of desert are essentially bare; plant growth is concentrated in channels and depressions where water accumulates when it rains. Environmental conditions and species found in the Sahara differ from those in the Namib Desert of southern Africa. In the latter, cold ocean currents facilitate the accumulation of dew on the desert, which helps to support plant life. Succulents (plants that retain water) and annual plant species typically account for most species found in desert ecosystems, with different plant species characteristic of different desert types (sand, gravel, or rock). The arid environments of southern Africa have a remarkable number of different species. Namaqualand, a region in northwestern South Africa, is renowned for the profusion of brilliantly colored wildflowers that appear after spring rains. D4 Mediterranean Shrub Lands The shrub lands of the northwestern and southern tips of the continent have Mediterranean climates, with warm, dry summers and mild, rainy winters. Unlike most of Africa, this climate supports distinctive types of temperate plant species. Mediterranean vegetation is xerophytic (drought-resistant), an adaptation to the limited rainfall and prolonged dry season that occurs during the summer months. The tree species typical of the North African shrub lands resemble those found elsewhere around the Mediterranean Sea, including wild olive, cork, juniper, and oak. Large areas of North African shrub lands have been damaged or destroyed through thousands of years of herding and agriculture. Environmental impact was pronounced during the 20th century, when rapid population increase and commercialization encouraged the expansion of agriculture into marginal, environmentally sensitive lands. The Cape region of South Africa has a distinctive ecosystem known as fynbos, in which fine-leaved evergreen shrubs predominate. It is one of the richest plant life biomes in the world, with some 8,500 species of plants in a relatively small area of about 90,000 sq km (about 30,000 sq mi). Over two-thirds of the species are endemic, meaning that they are found nowhere else in the world. Distinct subtypes of fynbos occur along the coast and in the adjacent mountains. In several other parts of southern Africa infertile soils, fire, and a lengthy dry season constrain vegetation growth. D5 Highland Vegetation In Africa's discontinuous areas of high mountains and uplands, altitude plays a significant role in determining climate and vegetation. On high peaks such as Kilimanjaro, vegetation changes as altitude increases: savanna vegetation near the base, then, in turn, zones of montane forest, bamboo, hagenia, heather, and high-altitude alpine moorland, with rock and ice at the summits of the very highest peaks. The montane forests include hardwood trees and many unusual plant species, including giant heather, giant groundsel, and giant lobelia. Growing conditions are also unusual due to the high temperatures during the day and very low temperatures that prevail at night. Some 4,000 species are associated with the African alpine zone, and three-quarters of these species are found only in Africa's montane forests. Other comparatively high-altitude regions have distinctive plant life. The highlands of Ethiopia contain scattered patches of montane forest with many species that resemble temperate deciduous trees. At higher elevations, tree cover largely disappears--except in deep valleys--and grasses, sedges, and heathers prevail. In the highlands of South Africa above 1,100 m (3,500 ft), vast expanses of temperate grasslands occur. In the highest parts of the Ahaggar and Tibesti mountains of the Sahara, some plant species resemble those of the Mediterranean region, isolated there when the region's climate became drier thousands of years ago. E Soils Like vegetation zones, soil regions in Africa are closely linked to climatic zones. Rainfall and temperature determine the growth of vegetation, which inhibits soil erosion and enriches soil with nutrients from decaying organic material, called humus. The luxuriant vegetation of tropical forest environments produces large quantities of humus, which is concentrated on the forest floor. In savanna grasslands, humus extends to a greater depth in the soil. The sparse vegetation of semidesert and desert regions gives rise to soils with little organic content. Rainfall and temperature also determine the intensity of chemical weathering, physical weathering, and leaching--all of which affect the development of soil types. Soil development is highly influenced by the soil's parent material--the rock from which it is derived--and by topographic relief. Much of Africa's soil is derived from ancient, quartz-rich rocks that produce generally infertile soils with high sand content. Soils formed in areas of younger volcanic bedrock tend to have higher clay and mineral content, and are therefore more fertile. Relief plays a major role in soil erosion, especially by water. Erosion removes topsoil from upper slopes and deposits eroded materials downslope. These erosion and deposition processes often create a gradation of soil types along a slope. African farmers take advantage of these variations in soil type and soil fertility by planting different crops at different levels of the slope. E1 Soil-Forming Processes Hot, humid tropical climates provide ideal conditions for chemical weathering, which gradually brings about the disintegration of parent rock material into soil particles. In drier climates, physical weathering--the breakup of parent material by the force of moving water and wind--is more important than chemical weathering. Soils in humid tropical regions are especially subject to leaching, the process in which smaller particles and minerals are carried by groundwater downward through the soil. When the upper layers of soil have been leached of critical nutrients, they are left primarily with iron and aluminum compounds, accounting for both their infertility and their typical brick-red or yellow color. Salinization and calcification are important processes in the development of soils in arid and semiarid regions. Salinization occurs when salts, dissolved in soil water, are carried upward through the soil and deposited on or near the surface as a result of evaporation. Few species of plants are adapted to survive in soils with high salt concentrations. Calcification is prevalent in moderately dry to semiarid environments, generally in grassland areas. Calcification involves development of a subsurface layer of calcium carbonate, carried downward from the upper soil layers. E2 Major Soil Types Despite the richness of vegetation, soils in the tropical forests of Central and West Africa are poor. The heavy rainfall of these areas is acidified as it passes through organic material on the forest floor and leaches most of the mineral content from the upper soil layers. The resulting soils--classified as oxisols--are quite infertile, forcing plants to gain most of their nutrient needs from decaying vegetation. Oxisols are reddish or yellowish in color, reflecting the high concentrations of iron and aluminum compounds in them. The soils of the moist boundary areas between the forests and savanna are subject to high levels of chemical weathering. The resulting ultisols are highly leached (but less so than oxisols), have low to moderate organic content, and are generally infertile. In savanna regions where there are moderate levels of seasonal rainfall, chemical weathering is less pronounced than in moister environments. Calcification occurs where calcium carbonate levels are high. The resulting soils are called alfisols. The organic content of alfisols is relatively high, and they are generally quite fertile. In Africa's arid and semiarid regions, low rainfall and sparse vegetation gives rise to aridisols. These soils are poorly developed, with little chemical weathering, infrequent leaching, and low organic content. Salinization is widespread, resulting in the concentration of mineral salts at or near the surface. In areas with less saline soils, irrigated agriculture is possible. Without proper management, however, irrigated aridisols may become infertile as a result of salinization or waterlogging. Soils in certain seasonally dry areas are heavy and have a high clay content. The clay in these vertisols expands when it is wet, then shrinks and cracks when dried. These soils are associated with river floodplains and former lake bottoms, notably the middle Nile Valley and Lake Chad Basin. Vertisols are quite fertile due to their high mineral content, and are used extensively to grow cotton and grain crops. Younger, less developed soils are classified as inceptisols. Included are the thin, rocky soils derived from younger volcanic deposits on the Ethiopian Plateau, young beach deposits in coastal regions, and active sand dunes in semiarid areas. Inceptisols are generally infertile. F Animal Life Africa teems with animals of all shapes and sizes. The continent has thousands upon thousands of species of mammals, fish, reptiles, amphibians, birds, and insects. Many of these animals are linked in an intricate food web. For example, hippopotamuses deposit large amounts of nutrients in bodies of water where they rest and defecate; these nutrients support abundant growth of plants, insects, and other smaller creatures that in turn provide food for species higher in the food chain. Other animals are linked in symbiotic relationships, such as between big game animals and birds known as oxpeckers. These birds eat the ticks that pester the large animals. F1 Continental Forest Animals African tropical forests offer many niches and habitats for different species. With a wide array of different types of food resources available year-round, they allow large numbers of species to coexist. Different habitats occur at different heights of the forest. Each of these habitats harbors a distinct set of animal species. The ground layer is strewn with nutrient-rich organic litter, providing a rich environment for many arthropods and insects, as well as creatures that feed on them, such as moles and rats. The forest canopy supports numerous species of mammals, including many kinds of monkeys and flying squirrels. Species of birds, reptiles, bats, and insects also abound. The forest floor tends to be less diverse, although its wildlife includes some of the largest and most fascinating species in Africa, including elephants, lowland and mountain gorillas, and okapis, giraffe-like animals found in the Congo Basin. Other species include duikers, bushbucks, forest pigs, giant pangolins (a type of armored anteater), and drills and mandrills (two species of baboon). Different areas of the African tropical forest vary in species diversity: For example, the relatively undisturbed forests of Gabon are more diverse than those in Nigeria, where there have been major human impacts on forest ecosystems. Overall, Africa's forests appear to support less biodiversity than the larger, more heterogeneous forests of the Amazon and Southeast Asia. F2 Animal Life on Madagascar Despite its proximity to the continental mainland, Madagascar's animal life developed in isolation after the island broke away from the rest of Africa about 135 million years ago. It is estimated that 90 percent of the species inhabiting its tropical forests are endemic, meaning that they are found nowhere else in the world. Madagascar has some 25 species of lemurs and 30 species of tenrecs, a type of insectivore. Other native mammal species include several civets and the fossa, a member of the cat family measuring almost 1.5 m (5 ft) in length. Madagascar's bird and insect populations are equally rich and are also largely endemic. Because more than 90 percent of Madagascar's forests have been affected by human activity, many species on the island face extinction because of loss of habitat. Many other notable species have already vanished, including the giant lemur, giant tortoise, and elephant bird. F3 Savanna Animals The savannas offer a narrower range of habitats than the forested regions, but nevertheless support exceedingly rich animal populations. The savannas of eastern and southern Africa are renowned for their big game animals, huge herds of herbivores, and abundant bird species. West African savanna regions tend to have less diverse fauna and smaller animal populations, primarily because of long-standing pressures from hunting and loss of habitat. Many species are adapted in particular ways to their environment. Giraffes, for example, have long necks and therefore can graze on vegetation higher than other animals can reach. Because rainfall and food supply are highly seasonal, numerous species are migratory. Africa is famous for its huge herds of savanna animals. In areas such as the Serengeti Plain in northern Tanzania, herds of herbivores, several thousand zebras or gnus (wildebeests) strong, can stretch for miles. Besides gnus, the savannas support a rich variety of other antelopes, from huge elands to tiny duikers; others include hartebeests, impalas, topis, oribis, kobs, and waterbucks. These animals provide the main food source for carnivores, including lions, leopards, cheetahs, and hyenas. Other species of large herbivores include elephants, black and white rhinoceroses, African buffaloes, giraffes, and hippopotamuses. Many smaller animals, including baboons, several species of monkeys, and a multitude of small carnivores and rodents, are also found. Africa's savannas harbor rich bird life. With more than 1,000 bird species, Kenya has one of the most diverse bird populations in the world. Birds of prey, including numerous hawks, eagles, and falcons, feed on smaller birds and other fauna, while vultures seek out carrion as a source of food. Brightly colored rollers, kingfishers, and bee-eaters are commonly seen in the air. Larks and pipits are widespread in the grasslands, as are flycatchers, bulbuls, babblers, warblers, and swallows. Other distinctive birds of the region include the crowned-crane, guinea fowl, ground hornbill, and marabou stork. Some species congregate in huge flocks, among them flamingos and red-billed queleas. The quelea is considered a pest by farmers because of the damage it does to crops. Savanna regions are also rich in reptile life. Nile crocodiles, as well as other smaller crocodile species, inhabit waterside environments. Various lizards abound, among them large Nile monitors and smaller species of chameleons and geckos. The savannas have many types of snakes, the most feared of which are various species of vipers, as well as cobras and mambas. The rock python is the largest snake, being known to attain a length of 8 m (25 ft). F4 Desert and Semidesert Animals Animals in arid environments must adapt to conditions such as water shortages, high temperatures, and a high risk of food scarcity. Some species adapt by migrating to other climes, while others are able to survive for prolonged periods without water. Sizes of animal populations vary from area to area, depending on food abundance; and from time to time, due to unpredictable and scarce rainfall. Rodent species, including the Nile rat, jerboa, gerbil, and hare, are common in arid and semiarid regions. Several species of gazelles are also found. Rodents and gazelles serve as prey for fennecs, other foxes, jackals, and hyenas. Ostriches, the world's largest birds, are also found in arid and semiarid regions. Other birds restricted to the deserts and their fringes include sand grouse and coursers. F5 Freshwater Fish The rivers and lakes of the northern semiarid and savanna regions--such as the Sénégal, Niger, and Nile rivers, and Lake Chad--have similar fish populations. Several species of catfish and the huge Nile perch are the mainstays of the fishing industry. Some fish species, such as the lungfish, survive the prolonged dry season by burrowing into the mud of drying streambeds and reemerging the following rainy season. Such is the biological diversity of fish in Lakes Victoria, Tanganyika, and Malawi that biologists consider these lakes critical to the study of evolution. Despite their relatively young age and close geographical proximity, these lakes have developed distinct and highly varied fish populations. Lake Malawi alone has about 540 species of fish--including some 500 species of cichlids--and 99 percent are endemic. To date, 290 species have been identified in Lake Victoria, half of them endemic. Lake Tanganyika has about 140 cichlid and 110 other fish species. F6 Marine Life The Atlantic Ocean off Africa's west coast has two cold ocean currents--the Benguela south of the equator and the Canaries to the north--as well as several areas where cold water rises to the surface. These zones of upwelling are rich in nutrients and support large fish populations. Fishing fleets off the coasts of southern and northwest Africa harvest species such as sardines, herrings, and tuna. Shrimp are harvested on the coasts of several West African countries. The waters of the Red Sea and Indian Ocean are considerably warmer than those of the Atlantic, supporting the development of coral reefs. These reefs provide for a great variety of fish species. Local fishers harvest many types of fish, but large-scale commercial fishing remains relatively unimportant. One famous rare species of Indian Ocean fish is the coelacanth, characterized as a "living fossil." Before it was discovered in 1938, experts believed it had been extinct for 70 million years. F7 Insects Africa has a vast insect population. As on other continents, insects play a critical role in African ecosystems. Some insects are of particular importance to humans as either transmitters of diseases, soil modifiers, or threats to crops. F7a Insects as Carriers of Disease In colonial times, Europeans referred to Africa as the "white man's grave," reflecting the fear of life-threatening tropical diseases for which non-Africans lacked natural resistance. The leading cause of death--among colonists and Africans alike--was malaria. The malaria parasite is transmitted to humans by the bite of the female Anopheles mosquito. The World Health Organization (WHO) launched a worldwide campaign to eradicate malaria during the 1960s by spraying homes with insecticides, draining breeding sites, and dispensing antimalarial drugs. The campaign failed: Parasites developed genetic resistance to drugs, mosquitoes became resistant to insecticides, and impoverished governments lacked the resources to develop a comprehensive strategy against the disease. Today, malaria remains Africa's leading cause of death. Various species of tsetse fly are another scourge of Africa. The tsetse transmits the Trypanosoma parasite, which causes the often-fatal disease trypanosomiasis, also known as sleeping sickness in humans and nagana in livestock. The prevalence of tsetse is believed to be a major factor in settlement patterns in Africa, including the low population densities of large areas of the savanna. Because cattle are especially vulnerable to trypanosomiasis, the full economic potential of vast areas of fertile grassland has not been realized. Certain colonial policies heightened the tsetse scourge: The creation of game reserves increased populations of wild animals that serve as natural reservoirs of the Trypanosoma parasite; and resettlement schemes increased human contact with tsetse and brought about major epidemics of sleeping sickness. An epidemic in the early 20th century wiped out some two-thirds of the population of what is now Uganda. Colonial control programs eventually succeeded in limiting, but not eliminating, the tsetse and the diseases it transmits. The black fly Simulium damnosum has had a major impact on settlement in Burkina Faso and several other countries in West Africa. This insect, which breeds in fastflowing streams, transmits a parasitic worm that is responsible for onchocerciasis, also known as river blindness, which causes blindness and severe skin problems. As rates of infection and blindness increased in villages close to fly-breeding sites, local economies were weakened and eventually the village sites were abandoned. The WHO initiated a control program during the 1970s, using insecticides to kill larvae of the fly, and chemotherapy to treat infected people. This program has succeeded in interrupting the transmission of the disease in most of the affected areas. F7b Termites The forests and savannas of Africa are home to some 400 species of termites. Termite mounds vary in size, depending on the termite species and on soil conditions: Some may be up to 9 m (30 ft) tall, with nests extending up to 15 m (50 ft) underground. Vast numbers of termites inhabit these nests; densities as high as 9 million termites per hectare (4 million per acre) have been recorded. Termites are both friend and foe to humans. Termite colonies enhance soil fertility by transporting and concentrating fertile subsoil clays near the surface and by increasing soil aeration. African farmers seek out termite mounds and plant crops around them--yields are usually higher from crops in these sites. Conversely, termites consume vast quantities of organic matter, and are blamed for increased soil erosion that may occur around termite mounds. F7c Locusts Three main types of locusts are found in the dry savanna and semidesert areas of Africa: the desert locust and the African migratory locust, found north of the equator, and the red locust, which occurs in south central Africa. These locusts occasionally congregate in large swarms to migrate in search of food. Following the direction of prevailing winds, they devour everything green in their path, including entire crop harvests. Spraying programs to control populations and routine monitoring to detect the first signs of swarming have reduced the serious threat that locusts once posed to agriculture. However, locusts can still sometimes cause significant damage at a local or regional scale. G Environmental Issues Africa is widely seen as a "devastated continent," where inappropriate human use of land has caused deforestation, desertification, and soil erosion on a massive scale. This view of Africa has greatly influenced academic research agendas and international aid programs, as well as public perceptions of the continent. But some scientists are increasingly questioning this view of environmental degradation. They emphasize the need to ascertain whether degradation is actually occurring, how human actions affect the process, and what conservation measures are needed. In some cases, Western viewpoints and ideas have led to misguided attempts at conservation that had no effect or even an adverse effect on the environment. At the same time, some African conservation methods were discovered to be much more effective. Going forward, many experts argue that conservation strategies must be sensitive to regional and temporal variations and should seek to preserve and build upon local indigenous knowledge. G1 Soil Erosion and Desertification Until recently, there was widespread consensus among scientists and policymakers that African soils were threatened by ill-advised traditional farming methods that increased soil erosion and desertification (the process in which soil dries out until almost no vegetation grows on it). Policy documents used limited, often flawed case studies to produce continent-wide generalizations in which worst-case scenarios were too often presented as typical. In reality, the nature and extent of soil erosion and desertification varies greatly throughout Africa and much of it is unrelated to human activity. For example, savanna regions are subject to wind erosion in the dry season, which is the primary cause of soil erosion in arid and semiarid environments. The Sahel, a semiarid savanna region located to the south of the Sahara, experienced a severe drought from the late 1960s to the early 1970s. In reaction, Western scholars propagated a popular view that the Sahara was expanding year by year, relentlessly enveloping once-productive land. Further research has shown that, while soil degradation was confirmed in some areas, in many parts of the Sahel there was little evidence of degradation, and none of steady desert expansion. During the colonial era, the perception of imminent crisis led to policy initiatives designed to preserve the soil. Colonial administrators attempted to control the perceived problem of erosion by enforcing restrictions on herding and agriculture, restricting the use of fire to clear land for agriculture, and installing grass and stone barriers along slope contours. These measures were generally resented by the local African population, and they had little impact on erosion rates. Similarly, attempts to control desertification through policies such as planting shelter belts of trees and restricting nomadic herding have had limited effect. Scientific research has demonstrated that indigenous African farming and herding practices are much less harmful to the soil than was formerly believed. Methods such as retaining farmland trees, growing crops on ridges, and interplanting different crops densely in a single field significantly reduce soil erosion. On the other hand, modern cultivation methods--involving the use of mechanical equipment, row cropping, and weed control with herbicides--greatly increase the risk of soil loss. Similarly, problems of soil erosion and degradation are greater in areas with fenced cattle ranches than in places where traditional livestock practices are followed, with animals grazing less intensively over a very large area. G2 Human Impact on Vegetation Little of Africa's vegetation is natural in the sense of being virtually unaltered by humans. Areas near settlements bear the particular marks of human impact: People plant trees for fruit, shade, and other uses; preserve beneficial wild species; and selectively clear less desired vegetation. Humans have had a major impact on the loss and degradation of Africa's tropical forests. Between 1990 and 2000 an estimated 5 million hectares (13 million acres) of forest were lost in Africa. The destruction has been especially significant in Madagascar and in West African countries such as Nigeria, Ghana, and Côte d'Ivoire, where population growth and agricultural development have been rapid and forest area is relatively small. Economic development schemes have harmed forests in many countries. Forests have been cleared for large-scale plantation agriculture, flooded under reservoirs by the construction of dams, and, in the case of the Niger Delta, harmed by development and pollution related to petroleum exploitation. While agricultural expansion has resulted in forest loss in many areas of Africa, traditional agricultural practices are not necessarily the cause. Recent studies in Guinea have documented significant expansions of forest cover during the 20th century through the deliberate interventions of humans, including the strategic burning of patches of forest. When practiced in moderation, burning helps replenish soil with nutrients from burnt vegetation and provides new seedlings with the space to flourish. Similar results have been found elsewhere in West Africa. G3 Threats to Freshwater Ecosystems Overfishing, pollution, habitat changes, and the ill-advised introduction of exotic species all pose a significant threat to the biodiversity of Africa's major lakes and rivers. Human impact has been especially severe in Lake Victoria. Signs of overfishing--declining size and volume of catch--have been evident in the lake since the 1920s. One response was to introduce new species to enhance the fishing industry: Four species of tilapia and the Nile perch were released into Lake Victoria in the 1950s and 1960s. While the fisheries initially benefited, the ecosystem was devastated. The Nile perch displaced the traditional predators, and by the 1990s about 60 percent of Lake Victoria's cichlid species had become extinct. Many rivers and lakes--particularly Lake Victoria--have also suffered from the introduction of the water hyacinth, a large ornamental water plant native to South America. The water hyacinth spreads rapidly and threatens fish and other water life in the rivers and lakes by depriving them of oxygen and causing significant changes in aquatic habitats. G4 Wildlife Conservation and Management Africa's animal life is under pressure, facing threats that include habitat loss from forest clearance, agriculture, and herding; hunting for food and profit; pollution from agricultural and industrial sources; and disturbance by tourists. As spaces for wildlife shrink and corridors linking areas of habitat are cut, the survival of healthy species populations--especially of larger animals and highly specialized species--becomes more tenuous. Addressing these problems is a very complex issue, especially because indigenous peoples have diverse needs for, and claims to, these resources. Thus, the need for protected spaces for wildlife often seems at odds with human needs. Wildlife protection has had a long history in Africa. Colonial conservation measures were imposed on African societies without consultation or consideration of the impact on local economies. Indigenous conservation measures, practiced for centuries, were ignored and sometimes undermined. In more recent times, threats to habitat and to wildlife have come increasingly from large-scale projects, such as dams, reservoirs, and irrigation schemes. Yet the solutions proposed to protect wildlife have generally continued to impose significant costs on local communities. Game reserves were first established by Africa's colonial rulers in the 1890s. Concern about the effects of hunting on big game led to the establishment of several national parks for wildlife conservation in the 1930s. The establishment of new parks and reserves continued throughout the colonial era, and postcolonial regimes followed suit. A sometimes uneasy mix of conservation and economic concerns--especially tourism--continues to provide the rationale for such initiatives. Some 5 percent of Africa's land area is designated as protected. However, protected areas vary between countries: While 30.2 percent of Botswana is designated as protected, the figure is only 2.6 percent for Madagascar. Also, some environments, such as semidesert and marine sites, remain underrepresented. Indigenous populations often remain ambivalent about wildlife conservation programs that restrict their access to farmland and pastures and set limits on killing wild animals for food. Governments have begun to experiment with comanaged protected areas, in which local communities are consulted about decisions, given priority access to jobs as guards and guides, and allowed limited access to the protected areas for hunting and other activities. The objective of these programs is to ensure that local communities feel they have a stake in successful conservation. The most effective of these programs--notably, Zimbabwe's Communal Areas Management Programme for Indigenous Resources (CAMPFIRE)--have succeeded in reducing poaching and increasing local incomes. There has been much controversy over the best way to stop the poaching of big game animals, particularly elephants, which are killed for their ivory tusks. In 1989 the Convention on International Trade in Endangered Species (CITES) voted to enforce a total ban on the ivory trade. Kenya and other African countries that had been severely affected by poaching were strong supporters of this ban. On the other hand, South Africa, Zimbabwe, and Botswana argued for limited elephant hunting and a controlled ivory trade as the best way to protect elephants. These countries have large and growing elephant populations, and have traditionally culled their herds periodically to maintain the health of herds and of the ecosystems supporting them. The Natural Environment section of this article was contributed by Robert Stock. III PEOPLE OF AFRICA Africa was the birthplace of the human species between 8 million and 5 million years ago. Today, the vast majority of its inhabitants are of indigenous origin. People across the continent are remarkably diverse by just about any measure: They speak a vast number of different languages, practice hundreds of distinct religions, live in a variety of types of dwellings, and engage in a wide range of economic activities. Over the centuries, peoples from other parts of the world have migrated to Africa and settled there. Historically, Arabs have been the most numerous immigrants. Starting in the 7th century AD, they crossed into North Africa from the Middle East, bringing the religion of Islam with them. A later movement of Arabs into East and Central Africa occurred in the 19th century. Europeans first settled in Africa in the mid-17th century near the Cape of Good Hope, at the southern end of the continent. More Europeans immigrated during the subsequent colonial period, particularly to present-day South Africa, Zimbabwe, and Algeria. South Asians also arrived during colonial times. Their descendants, often referred to as Indians, are found largely in Uganda, Kenya, Tanzania, and South Africa. A Demographics In 2008, 955 million people--or about 13 percent of the world's population--lived in Africa. The most populous countries are Nigeria, Egypt, Ethiopia, and the Democratic Republic of the Congo (DRC). Distribution of the population is highly uneven. Some parts of the continent, particularly the vast Sahara, have few permanent residents. Others rank among the world's most densely populated areas, notably the Nile Valley of Egypt; the Atlantic coastal stretch from Côte d'Ivoire to Cameroon; Rwanda; Burundi; and South Africa's province of KwaZulu-Natal. Overall, Africa's population density was 32 persons per sq km (83 persons per sq mi) in 2008. Until the mid-20th century census-taking was rare in Africa. Although most African countries have by now conducted at least several counts of their populations, reliable data on vital statistics are limited. Nonetheless, it is clear that Africa's population has grown rapidly in recent decades. The continent-wide population growth rate peaked at 3.43 percent in 1979 and remained relatively high through the 1980s, averaging 2.69 percent. Rates have lowered since. In 2005 Africa's growth rate was 2.08 percent, which is still high compared to other continents. In general, West, East, and Central Africa have experienced the fastest growth and North and southern Africa the slowest. A1 Birth Rate In 2005 Africa's overall birth rate was 35.3 births per 1,000 people, the highest among the world's continents. The countries of North Africa have markedly lower rates than most sub-Saharan countries. South of the Sahara, fertility rates tend to fall in the 5 to 7 range (meaning that, on average, women give birth to 5 to 7 children over the course of their lifetimes). African societies have traditionally seen large families as signs of wealth and prestige, and value the presence of children in everyday life. Children are also an important source of labor, especially on farms, and eventually become the primary providers of assistance to elderly parents. In addition, a greater number of children means more marriages, resulting in wider family support networks, a crucial consideration in a continent where life is often hazardous. For all these reasons, to be childless is typically a cause for concern and often pity. As a result, birth control has not been accepted to the degree it has in other parts of the less developed world, such as Southeast Asia. The major exceptions are found among members of the newly emerging urban middle class, who have adopted nuclear family arrangements modeled on those in Western societies. Parents in nuclear families do not receive the higher level of support offered by extended families, so they find children costly in terms of money and time. These African families have therefore begun practicing birth control. A high fertility rate translates into a young population, which has several important implications. It assures continued population growth, short of disaster occurring, into an indefinite future. Even if the fertility rate declines, the population will continue to grow because of the large number of women who will have reached their childbearing years. Population growth strains a nation's child services, especially the provision of education and health care, and the problem becomes particularly acute when poverty is as widespread as it is in Africa. Competition for jobs intensifies as more and more people enter the labor market, and higher levels of unemployment can lead to increasing crime rates and wider social unrest. A2 Death Rate and Life Expectancy Africa's death rate--14.2 deaths per 1,000 people in 2005--is also the highest in the world. Again, the countries of North Africa have significantly lower rates than those of sub-Saharan Africa. Infant and child deaths, from an array of infectious and parasitic diseases, traditionally are the main contributors. Vaccination campaigns have helped lower death rates among children since 1980. However, over the same period, an increasing incidence of infection with the human immunodeficiency virus (HIV) that causes acquired immunodeficiency syndrome (AIDS) has actually resulted in the decline of life expectancy in some countries. For example, Botswana, after achieving a life expectancy of 60 in the early 1990s, saw the figure fall into the 30s in the first decade of the 21st century. The country's population will soon be in decline due to the loss of large numbers of young adults to AIDS and the children they would have produced. South Africa is in a similar predicament and several other countries may soon be as well, depending on whether or not infection rates can be lowered. Across the continent, life expectancy in 2005 averaged 50.4 years. A3 Migration Migration is a commonplace African phenomenon. Traditionally, migration was largely associated with the search for new and better farm or grazing lands. Some herders migrated seasonally, moving their livestock to available water and forage sites. During colonial times, labor migration to mines and plantations became common. More recently, increasing numbers of people have been migrating to Africa's cities, which are perceived as places of opportunity not only to meet basic needs but to fulfill higher economic or social aspirations as well. Cyclical migration is also very common, as people move back and forth between cities and their home areas. Most Africans seek to maintain connections with the places where they were born. Refugees make up another group of migrants. In total, Africa contains about 30 percent of the world's refugee population, as classified by the office of the United Nations High Commissioner for Refugees. People generally flee turmoil in their home countries and become refugees in adjacent countries. Recent examples include southern Sudanese fleeing to Kenya, and Rwandans fleeing to Tanzania and the DRC. In some cases, turmoil grows worse in the nation harboring refugees, so the two countries literally exchange refugees. This happened in the late 20th century between Ethiopia and Somalia, and between Liberia and Sierra Leone. Most refugees eventually return to their home countries, although some manage to find new lives in their country of refuge. Intercontinental migration is much less common. While many people in former French colonies have moved to France, for the most part their goal has been to earn enough to send money home periodically before returning themselves. An individual may repeat this process several times during his or her adult years. Several African nations have faced a so-called brain drain, as skilled and professional workers find better employment opportunities elsewhere, especially in Europe and North America. These workers may or may not leave permanently. In the second half of the 20th century, many Europeans left for good. Large numbers of settlers in Algeria returned to France during the Algerian War of Independence (1954-1962), and since 1980 many white South Africans and Zimbabweans have departed. During the 1960s and 1970s political pressures and deteriorating social and economic conditions led many South Asians to flee Uganda. A4 Urban Growth Only 37 percent of Africans live in urban areas, making Africa the least urbanized continent. At the same time, however, it is also the most rapidly urbanizing continent. Africa's major cities, often national capitals, are the primary destinations for the vast majority of migrants, and some experience population growth rates of 8 to 10 percent per year. Dozens of African cities now have populations of more than 1 million. The largest cities in Africa include Cairo, Giza, and Alexandria in Egypt; Kinshasa, DRC; Casablanca, Morocco; Cape Town and Johannesburg, South Africa; Addis Ababa, Ethiopia; Lagos, Nigeria; and Luanda, Angola. Two of the world's largest metropolitan areas are located in Africa: The combined Cairo-Giza metropolitan area has about 12 million inhabitants, and Lagos and its surrounding suburbs are home to close to 17 million people. By 2015 the population of the Lagos metropolitan area is expected to be more than 23 million. Great differences in wealth and living standards are characteristic of all large African cities. Job opportunities in cities have not kept pace with population growth. Rates of unemployment in urban areas often exceed 50 percent, and most jobless people are young, male, and undereducated. Many residents earn their incomes from informal occupations such as selling newspapers and magazines, shining shoes, running errands, cleaning, and collecting trash. Begging, prostitution, and theft are also ways of making a living. Crime is on the rise in Africa's large cities. Carjackings, sometimes accompanied by assault and murder, have become more common. Urban housing also tends to be in short supply and thus relatively expensive. Workers often reside on the outskirts of cities in what are politely called unscheduled settlements (more commonly known as shantytowns) where rents are cheaper. While usually lively places to live, they are also overcrowded and lack basic services such as sewage systems and clean water supplies. This raises the risk, especially for children, of contracting infectious and parasitic diseases. Cholera is a particularly dangerous threat in urban areas. To reverse the trend of overconcentration of population in urban areas, several countries have established new capital cities. The Nigerian government moved the capital from Lagos to the new city of Abuja in 1991, and Tanzania has tried since the 1970s to relocate its capital from Dar es Salaam to Dodoma, a small city in the center of the country. In neither case has the change worked in terms of population movement: Migrants continue to flood Lagos and Dar es Salaam. As cities grow, so too does their ethnic diversity. Although mixing of ethnic groups occurs more than in the past, different groups tend to segregate themselves in different neighborhoods. This is especially true when groups have a history of political conflict. For example, in Nairobi, Kenya, the Luo and Kikuyu seldom mix; the same holds for the Igbo and Hausa in Nigeria's largest cities. Immigrants, such as Mozambicans in South Africa, often cluster in particular districts. Many older West African cities feature so-called "stranger quarters" for immigrants. B Language and Ethnicity African people identify themselves, or have been identified by others, as members of certain ethnic groups. While this identification can be based on a number of different criteria, a person's mother tongue is often the most common determinant. B1 African Languages The number of distinctive languages spoken in Africa is open to debate. Some experts put the number at around 2,000, while others count more than 3,000. Virtually all of these languages originated in Africa. The most widely spoken indigenous African language is Swahili, spoken by nearly 50 million Africans, followed by Hausa and Yoruba, each with more than 20 million speakers. Several languages have only a few thousand speakers. Scholars generally recognize four African language families: Niger-Congo, Afro-Asiatic, Nilo-Saharan, and Khoisan. Most Africans are multilingual, meaning that they speak two or more different languages. Few can afford to be otherwise, since daily life often brings people into contact with others who speak different languages. For instance, more than 50 languages are spoken in Nigeria alone. Tanzania, with significantly fewer people, has nearly 100 languages, including at least one from each of the four language families. North Africans and converts to Islam have spoken Arabic for centuries, and the use of European languages has spread across the continent since the dawn of colonialism. Today, the language of a country's former colonial rulers often serves as its common tongue. B1a Niger-Congo Language Family Niger-Congo is by far the largest language family. Niger-Congo languages are spoken by more than half the continent's people, from the Sénégal River Valley in West Africa to the shores of the Indian Ocean in the east to the Cape of Good Hope in the south. Among its several language branches is Bantu. In one of the world's great human migrations, Bantu speakers spread east and south from a starting point in what is now Nigeria and Cameroon beginning about 4,000 years ago. Today, various Bantu languages are spoken across most of the southern half of Africa. The Kongo of the DRC, the Ganda of Uganda, the Chagga of Tanzania, and the Shona of Zimbabwe are examples of peoples speaking Bantu languages. Kwa is another large Niger-Congo branch; Kwa language speakers include the Yoruba of Nigeria and the Ashanti of Ghana. Swahili, widely spoken in East Africa and parts of Central Africa, is an interesting medley of languages. Its basic grammar and syntax are of Bantu origin (so it is classified as a Niger-Congo language), but many words come from Arabic, with a smattering of Portuguese, English, and even Persian words appearing as well. Developed as a trade language along the Indian Ocean coast, Swahili spread inland with merchants in the 19th century. It serves as an official language of Tanzania and Kenya. B1b Afro-Asiatic Language Family Throughout much of northern Africa, Afro-Asiatic languages predominate. One branch of this language family is Semitic, which includes Arabic, as well as Amharic and Tigrinya, which are spoken in the Horn of Africa. The Cushitic branch extends south from the Red Sea coast, through the Horn of Africa, and into central Kenya and Tanzania. Its most commonly spoken languages are Somali and Oromo. The Chadic branch includes Hausa, widely spoken in Niger and northern Nigeria. Berber is yet a fourth branch, and includes the language of the Tuareg of the Sahara as well as many other tongues spoken in and around the Atlas Mountains of northwestern Africa. B1c Nilo-Saharan Language Family As Afro-Asiatic languages spread over the last several thousand years, they seemed to have pushed out many Nilo-Saharan languages. Nilo-Saharan speakers today are largely confined to portions of the central Sahara and the savanna lands of East Africa. The Masai of Kenya and Tanzania speak a language in the Eastern Sudanic branch, as do the Nuer of southern Sudan. Scholars disagree over the correct classification of Songhai, a language spoken along the banks of the middle Niger River. Songhai is usually placed within the NiloSaharan family, but some linguists now see it as unrelated to any of the four families. If Songhai truly is separate, then its speakers either represent the last survivors of a once far-flung language family, or they are descendants of migrants from some unknown place. B1d Khoisan Language Family The Khoisan language family is named after its two primary representatives: Khoikhoi and San. These languages are distinctive for their use of click sounds, which speakers produce by sucking in air. Once widespread across southern Africa and possibly East Africa, Khoisan speakers were largely displaced by Bantu migrants over the last millennia. Today, San speakers (known as San) number only about 50,000, living in and around the Kalahari Desert in Botswana and Namibia. The Nama of Namibia are one of the last representatives of Khoikhoi speakers. Distantly related to them are the Sandawe of central Tanzania. It is unknown whether they represent a surviving indigenous Khoikhoi population or descendants of later immigrants. B2 Formation of Ethnic Identities If ethnicity is considered synonymous with how people are identified, both by themselves and others, then throughout Africa, language serves as its primary marker. Language links people to a specific place of origin, which, in turn, signals a shared cultural history. In South Africa, for example, the Zulu and Xhosa speak languages that are almost identical, but the minor differences are enough for people to make the distinction between the two groups. This is important to their sense of identity because the Zulu and Xhosa have followed very different paths over the last several centuries of history. Some peoples have even deeper roots. The Songhai identity existed even before the group ruled a vast West African empire in the 15th and 16th centuries. By way of contrast, the ethnic identities of many other peoples are more recent and often derive largely from external sources. The Gogo of central Tanzania are a case in point. In the mid-19th century they lived in many small clan-based chiefdoms that had no sense of being part of a wider Gogo group, even though they shared the same language. However, the phrase "gogo" was a part of several of the clans' names, and their Nyamwezi neighbors picked up on this as a way to refer to all of them. When Arab and Swahili traders arrived in the area in the mid-19th century, they adopted this designation and passed it along to the first Europeans to enter the area. Because of repeated use, the name Gogo became accepted, eventually by the people themselves. This process of naming groups on the basis of language similarities gained speed during the colonial era. This was done largely for administrative purposes, allowing colonial rulers to appoint chiefs to recruit labor and collect taxes from so-called tribes occupying specific designated areas. Anthropologists followed suit and classified ethnic groups by language similarities and locale. Without these external effects, it is unlikely that many of the overarching African ethnic identities now taken for granted would have developed. The Hutu and Tutsi of Rwanda and Burundi demonstrate that factors other than language play roles in the formation of ethnic identities. Prior to the colonization of these regions, "Hutu" and "Tutsi" designated what might best be called classes, with the former referring to farmers and the latter designating cattle keepers. The two classes shared a common language, and people moved from one to the other by way of marriage or the ownership of cattle. When the Germans and subsequently the Belgians colonized the region, they assumed that the Tutsi were rulers, and thus privileged them with education and positions of authority in the colonial state. By the mid-20th century the boundaries between Hutu and Tutsi identities hardened to where they started to conceive of themselves as separate peoples. Since the independence of Rwanda and Burundi, this separateness has periodically led to one group treating the other as a hated enemy in efforts to rule the countries. In a real sense, they now conceive of themselves as separate ethnic groups. Way of life, not language, is what differentiates some ethnic groups from each other. In Tanzania, the Masai and Arusha speak the same language, but those who herd cattle are known as Masai, while those that gave up herding to become farmers are known as Arusha. Similarly, not too long ago, whether or not a person herded sheep distinguished Khoikhoi from San in the Cape region of South Africa. In these cases, people who changed occupations ended up changing their ethnic identities as well. A person's religion sometimes is the crucial factor defining his or her identity. This is what differentiates Christian Copts from their Muslim neighbors in Egypt. In addition, people sometimes identify themselves as Arabs simply because they adopted the religion of Islam and developed supposed genealogical links to the Prophet Muhammad. An interesting case of ethnicity involves the pygmy hunter-gatherers of equatorial Africa, among whom the Mbuti of the Ituri region of the DRC are best known. While there are indications that the various pygmy groups had their own unique languages at some point, they all adopted the languages of the nearby Bantu farmers with whom they interacted. In this case, occupation, residence, and physical differences all came together to create a sense of ethnic distinctiveness that both sides recognize. Liberia is home to Americo-Liberians, a people who trace their ancestry to freed slaves from North America. Use of English, the Protestant religion, and a wide array of other American cultural traits immediately set them apart from their indigenous African neighbors, over whom they ruled until being ousted from power in 1980. Upon independence, most African countries sought to create national identities for their people. These have yet to develop to any significant degree, and thus ethnic identities--whether forged long ago or only relatively recently--are what most people hold onto as an indication of where their true loyalties reside. Ethnic politics have thus become commonplace in Africa, with Rwanda and Burundi illustrating the extreme end of the scale. Zimbabwe is wracked by hostility between Shona and Ndebele. In Nigeria, Yoruba, Igbo, and Hausa compete, sometimes violently, with each other and with other minority groups. At the other end of the scale, ethnic politics is of little importance in Tanzania, which is so diverse that no group is particularly powerful. Sometimes older ethnic rivalries become submerged beneath other differences. This has happened in Sudan, wracked by a decades-long civil war between the Islamic, Arabic-speaking north and the non-Islamic, non-Arabic-speaking south. This conflict has put on hold long-standing disputes between the Dinka and Nuer of the south, which could surface again if the civil war were resolved. C Religion If religion is defined as a set of beliefs and practices related to moral behavior on earth and to life after death, then each African society developed its own distinctive version. Despite the diversity, several common themes are fairly widespread. One is the belief in a creator, who brings the universe into being and then departs, perhaps to the sky or to some distant place like a mountaintop. Another commonality involves the importance of ancestors. Death does not end one's existence, rather it moves one to a non-earthly realm to congregate with those who have gone before and those who will come after. Various rituals, including sacrifice, are conducted to honor and placate ancestors, to ensure that they help rather than cause trouble for the living. This is often referred to as "ancestor worship," which is a misnomer: It is not so much worship of ancestors as it is recognition of the importance of community--past, present, and future. A third commonality is the presence of religious specialists, including rainmakers, healers, diviners, and priests, represented in various proportions depending on the African society in question. Yet another common element is the pervasiveness of religion in everyday life. Spirituality is present in sacred places, art, music, dance, storytelling, and ceremonies such as name giving, initiation, and marriage. Indigenous religions remain widely practiced throughout sub-Saharan Africa. In many countries, adherents to indigenous belief systems make up more than 20 percent of the population, and in some--notably Liberia, Benin, Sierra Leone, Central African Republic, and Mozambique--more than 50 percent. The first world religion to reach Africa was Judaism, which spread into Egypt sometime during the 2nd millennium various Berber communities to the west. In addition, during the 1st century BC BC. Subsequently, Jewish people may have converted Jewish migrants crossed the Red Sea from the Arabian Peninsula and settled in the northern highlands of what is now Ethiopia. Over time, they won converts from the local populations and eventually formed a distinctive Jewish community called Beta Israel (referred to derogatorily as Falashas in Ethiopia). During the first centuries AD Christianity spread across North Africa, more by conversion than migration. In Egypt, the Christian sect of Monophysitism gained preeminence, and Egyptian Monophysites became known as Coptic Christians, or Copts (see Coptic Church). From Egypt, Coptic Christianity spread south to Nubia, and reached Abyssinia during the 4th century, becoming the state religion of the Kingdom of Aksum and subsequent Ethiopian states. Catholicism prevailed over rival Christian sects in northwestern Africa with the help of Saint Augustine, an Algerian and one of the framers of Western theology. In 639 Islam began its march across North Africa (see Spread of Islam). For the most part, even though Islam was brought by conquering armies, conversion was mostly voluntary. Converts were quickly won in northwestern Africa, where many people saw Islam as a vibrant spiritual and material alternative to a decaying Christian world. Scattered Catholic communities did, however, manage to survive in North Africa into the 15th century. Conversion to Islam moved more slowly in Nubia and in Egypt, where the Coptic Church is still strong. In the 8th century Arab merchants brought Islam to coastal communities along the Horn of Africa, and the religion subsequently spread inland to other peoples, notably the Somali. In the 12th century, and possibly earlier, Islam gained adherents farther south along the Indian Ocean coast in what is now Kenya and Tanzania. Another wave of Jewish immigration occurred in the late 15th century, when Christian armies reconquered the last Muslim-ruled areas of Spain. Jews in Spain were given a choice between exile or forcible conversion to Christianity, and many Jews crossed into North Africa, where they lived in peace with their Muslim neighbors. In the mid-19th century, European missionaries reintroduced Christianity to Africa, and the process of winning converts picked up speed during the colonial era. Virtually all of the major branches of Christianity, and many of the minor ones, established mission stations in Africa, leading to an intricate pattern of religious denominations. Africans found conversion to Christianity attractive because the missionaries offered health services and educational opportunities for their children. However, Christian missionaries made little headway in Islamic strongholds and the continent therefore became divided between an overwhelmingly Islamic north and a more Christian south. Roughly speaking, latitude 10° north serves as the dividing line from West Africa until East Africa, where it swings south of the equator to about 8° south. While Christians are few in number north of the line, Muslims are more common to the south of it. In Malawi and Mozambique, for example, 15 to 20 percent of the population count themselves as Muslims. Violence sometimes erupts between Islam and Christianity along the dividing line. This has been an ongoing social issue in Ethiopia for 800 years. Since 1970 Chad and the Sudan have seen ongoing strife and civil wars between the Islamic north and Christian-indigenous south. Sectarian violence has also occurred in Nigeria since the late 1990s. For the most part, however, the two religions are not in competition with one another and the continental dividing line seems unlikely to change. New churches combining Christian doctrine and rituals with indigenous African ones are becoming increasingly common. Zambia and Zimbabwe have provided particularly fertile grounds for the growth of these syncretic churches. In Zimbabwe, 40 percent of the population claims membership in a syncretistic church, compared to 22 percent in more conventional Christian denominations. D Cultural Activity Africa's cultural traditions are extremely diverse. Traditionally, art, music, and oral literature served to reinforce existing religious and social patterns. During the colonial period, some educated city dwellers rejected traditional African cultural activities in favor of Western cultural pursuits, but a cultural revival sprang up with the rise of African nationalism and independence in the mid-20th century. Arabic written literature has a long history in North Africa, while European-language literature has developed more recently. The governments of most African nations sponsor national dance and music groups, museums, and to a lesser degree, artists and writers. See African Art and Architecture; African Music; African Literature; African Theater. E Education Africans value education, and all governments see improving educational access and quality as essential to national economic and political development. Despite scarce financial resources, many countries have made noteworthy achievements in raising literacy rates in recent decades. Adult literacy rates of 70 percent or more are characteristic of East, Central, and southern Africa, except, notably, in Somalia, Angola, Ethiopia, and Mozambique. Gains have been less impressive in West Africa: Many countries still have literacy rates below 60 percent, and the rates in Niger, Burkina Faso, and Sierra Leone are among the world's lowest. Cameroon, Ghana, and Nigeria are notable exceptions, with particularly high literacy rates. Libya, Tunisia, and Algeria in North Africa have rates of 90 percent or higher. Females have significantly lower literacy rates than males across most of Africa. Compulsory school attendance, starting at either 6 or 7 years of age and lasting until the ages of 11 to 16, is now universal in Africa. In many instances, education is free. A major obstacle to universal education is the problem of providing enough teachers, schools, and classroom materials to meet children's needs, especially in remote rural areas. Huge national debts, the economic austerity measures designed to eliminate them, and military expenditures have all limited the funds that most countries have available to devote to education. Another obstacle to ensuring that all children receive education is the fact that they are still an important part of the workforce across Africa. They provide childcare, work farms and herds, and perform a range of other menial jobs, such as drawing water and collecting firewood. Parents may also lack the financial means to send their children to school, or may be forced to choose which ones can go and which ones cannot. Boys are usually given preference over girls in access to education and they typically stay in school much longer. The rationale for this is based on future income-earning potential: As matters currently stand, males have access to more and better paying jobs than females. Deteriorating economic conditions have actually led the income-earning and literacy gaps between males and females to widen even more. Universities have space for only a tiny fraction of secondary school graduates and competition to secure admittance is intense. Those who are admitted are not guaranteed a good education, however. University libraries are often poorly stocked and, most critically, lack up-to-date scientific journals. Computers are few and Internet access rare. Most campuses were built in the 1950s and 1960s and have deteriorated, the more so because of limited funds for maintenance. The quality of higher education is also affected by frequent student protests over issues ranging from poor living conditions to politics. On many occasions governments have responded with force and closed campuses for considerable periods of time. While faculties are usually of high quality, with many members having been trained in Europe and North America, the conditions severely constrain what they can do. As a result, many look outside Africa for employment, which contributes significantly to Africa's brain drain. F Health A combination of new diseases and reemerging old ones is putting the lives of millions of Africans in serious jeopardy. At the top of the list is HIV/AIDS, which is devastating much of sub-Saharan Africa. National health services are under serious stress as more and more funds and personnel have to be devoted to treating and caring for AIDS victims. This has drawn attention and resources away from other health problems, such as malaria and other infectious diseases. While various environmental and social issues can be identified as the cause of these afflictions, the real culprit is poverty. Until poverty is controlled, Africa's health situation will remain precarious, and doubly so for the most vulnerable: children. F1 HIV/AIDS To date, more than 70 percent of the victims of HIV/AIDS worldwide have been Africans. The world's first case on record is traceable to a plasma sample from a man who died in 1959 in the Belgian Congo (present-day DRC), but clinical identification of the disease was not possible until the early 1980s. By then it had already reached epidemic proportions, with Uganda and Rwanda as the epicenter of occurrence. In subsequent years, the epicenter moved progressively southward, and now Botswana and South Africa are seeing the highest rates of infection. As yet, HIV/AIDS has progressed more slowly in West Africa, with the exception of Côte d'Ivoire, which has been hit hard. Rates are increasing, however, especially in Nigeria. West Africa also has cases of HIV-2, an apparently less virulent strain of HIV that seems to result in lower death rates. Few cases of HIV infection have as yet been reported in North Africa. Two modes of transmission account for virtually all cases of infection in Africa. The most significant has been heterosexual intercourse. Spread of the virus has been facilitated by a tradition of men having multiple sexual partners. The increased mobility of the African population has also helped the spread of HIV. The earliest lines of transmission were along roads carrying heavy truck traffic, with the infection points being rest stops where prostitutes served truckers. Both populations soon became infected and began spreading the disease to others. As it has progressed, infection rates have grown more rapidly among females, especially younger ones. Several factors are responsible for this trend. First and foremost, condom use is limited, either because its protective value is unknown or because it is disliked. In addition, teenage African girls often start their sex lives with older men--whether married to them or not--who are more likely to be infected than boys their age. At the same time, as knowledge of AIDS has spread, men have sought to have sex with even younger girls in the belief that they will not already be infected. And, in many large cities such as Nairobi and Cape Town, cases of rape are on the rise. The increase of HIV among women brings about the second major mode of transmission, which is mother-to-child. More and more babies are entering the world infected, and many healthy newborns are infected through their mothers' milk. Transmission through homosexual sex and intravenous drug use are uncommon in Africa. In general, African governments have been slow to respond to the HIV/AIDS epidemic, or even to admit that a problem exists. Two significant exceptions are Uganda and Zambia, where efforts to halt the spread of HIV/AIDS date to the mid-1980s. The Ugandan program has been especially effective, and the disease there is receding. Zambia has also begun to see infection rates fall among its most vulnerable population, pregnant teenagers. The impacts of the HIV/AIDS epidemic are many and far-reaching. Countries where rates are very high, such as Botswana, will soon notice a "missing" adult population, leaving the country numerically dominated by the elderly and young. Numbers of orphans are on the rise, an unusual situation in Africa, where extended families and communities traditionally provide childcare. The missing adult population has already begun to affect economic productivity across the board, whether on farms or in factories. The teaching profession has been especially hard hit. AIDS is now by far the leading cause of death among teachers in the Côte d'Ivoire, and Zambia has found it cannot replace the number of teachers who have died or fallen ill. F2 Malaria Often called the "silent killer" due to the lack of attention it receives, malaria is spread by the bite of the female Anopheles mosquito. Worldwide, the disease afflicts between 300 million and 500 million people annually, and 90 percent of the cases occur in tropical Africa. In terms of mortality, children under age five are the most vulnerable group, with some 700,000 dying in Africa each year. This death toll exceeds that from AIDS. Adults are less likely to die from malaria, but still suffer from the sickness. Infection often peaks during the rainy season, and higher rates of bedridden workers affect the agricultural productivity of families, communities, and nations. Experts estimate that the annual costs of malaria treatment and lost productivity due to malaria total between $2 billion and $3 billion for the continent as a whole. The World Health Organization (WHO) began malaria control programs in 1948, spraying mosquito-breeding sites with insecticides and administering antimalarial drugs. For a time, it appeared that the disease might be eliminated, or at least brought under control. But since the late 1970s malaria has resurged. Mosquitoes have developed resistances to insecticides, as have the malaria parasites to traditional chloroquine-based antimalarial drugs. Urban malaria is spreading, largely as a result of the growth of squalid shantytowns that provide numerous pools of standing water where mosquitoes can breed. Civil conflict and natural disasters such as floods are other contributors to malaria's spread. The seriousness of the problem led the WHO and other international groups to launch Operation Roll Back Malaria in 1998. This operation aims to intensify monitoring, prevention, and treatment efforts, with the ultimate objective being the development of an antimalarial vaccine. F3 Other Afflictions Tuberculosis is another age-old disease that has become more widespread since the early 1980s, largely because it is a common opportunistic infection in AIDS cases. Drug-resistant varieties of tuberculosis are making treatment more difficult for all sufferers. Cholera, once uncommon on the continent, is now endemic in Africa. Outbreaks are associated with contaminated water supplies, and contamination has become ever more common in both rural and urban areas. Malnutrition is another widespread health problem among infants and young children. Many babies are born underweight, often because their mothers suffer from malnutrition. Studies have shown that many African children experience a slowdown in growth following weaning, when their diet suddenly shifts from high-protein, high-energy mothers' milk to predominantly starchy foods. Malnourished children often develop protein-energy malnutrition conditions such as marasmus (essentially infantile starvation) and kwashiorkor, characterized by body swelling. Both conditions can be fatal, the latter often in association with infectious and parasitic diseases such as measles and malaria, as well as diarrhea. The People of Africa section of this article was contributed by James L. Newman. IV ECONOMY Since prehistoric times, the majority of Africans have been farmers and herders who raised crops and livestock for subsistence. In precolonial times, a few African states developed long-distance trade networks based on the exchange of raw materials and some specialized local goods. Starting in the 15th century, European colonization of Africa brought overseas demand for certain agricultural and mineral products. The colonizers built new transportation networks and introduced technological innovations and new crops. At the same time, they exported millions of able-bodied Africans as slaves, exploited African labor within the continent, and undermined local industries, crafts, trade networks, and governments. By the mid-20th century, European colonies in Africa had established one-way trade systems in which Africa's wealth of raw materials were exported to enrich foreign coffers, with little regard for development within Africa. As decolonization began in the late 1950s, the African economy was divided into two distinct sectors. Most of the population took part in the traditional rural sector, which featured subsistence production of food and simple manufactured products. The remainder was involved in a relatively modern sector, based in cities and mining and plantation centers. There, Africans worked for wages, producing mineral or agricultural raw materials for export to industrialized countries. Although people in most rural communities earned some money from seasonal work in the cities and modern industrial centers, the two sectors were largely separate. In subsequent decades, African governments pursued various economic development initiatives in an attempt to improve the living standards of their people. In many countries, these efforts led to the growth of manufacturing of consumer goods and other products. Services--in education, health care, civil services, and other areas--also grew in economic importance. Development efforts led to a greater degree of interaction and movement of people and money between the modern and subsistence sectors of the African economy. Yet, by the early 21st century, the sectors were still far from integrated. Most of the population still pursued traditional subsistence activities, which continued to provide sustenance for the majority of Africans. At the same time, despite increasing levels of industrialization in many countries, Africa's raw materials continued to be produced primarily for export. A Traditional Subsistence Sector Despite economic development efforts, the traditional subsistence sector is a constant in the African economy. In general, the majority of African people farm, herd livestock, fish, make handcrafted products, and trade their goods much as they have for hundreds of years. Farming is by far the most important subsistence activity, and it dominates rural production in the tropical forest and tropical savanna zones of West, Central, and southern Africa. Traditional agriculture is basic and at best yields enough food and income for the household to survive. The average rural household has no access to scientifically improved seeds, farm machinery, or sophisticated methods of farm management. On most African farms, the soil must be worked with hand tools or small, animal-drawn plows. Use of artificial fertilizers is almost nonexistent. Insects and vermin are constant threats, sometimes eating away more than half of the crops. Farmers raise crops primarily to supply food for the family. However, there may be small surpluses, and these are sold to purchase other foods and essential goods. Cottage industry employs close to one-third of the rural labor force, not counting the many farmers who also engage in this activity on the side. It is largely responsible for the local supply of clothing, footwear, farm implements, and construction materials, as well as for processed foods. This sector also produces crafts, cloth, jewelry, and decorative artifacts to sell to tourists in urban areas and at tourist attractions. Small-scale commerce, taking place in small, often periodic, markets, is vital to people's sustenance in Africa's rural areas. At these markets, rural Africans sell crop surpluses and cottage industry products to traders who, in return, sell them goods such as spices, condiments, kerosene (for domestic lighting), soap, matches, batteries, clothing, and spare parts for bicycles and carts. The small-scale traders then sell the crops and manufactured products to larger-scale traders. These smallscale traders have played a crucial role in bringing the subsistence sector into the larger economy by buying farm products and making consumer goods available to the rural producer. Migratory herding, based on extensive and frequent movement of livestock, declined in importance over most of Africa in the second half of the 20th century. The area required for migratory herding has been greatly reduced as pasturelands have been taken over for agriculture--particularly modern plantations--and wildlife reserves. Fishing is a minor subsistence activity in most of Africa because of a general scarcity of good fishing grounds and because most of the continent's rural population lives in the interior. B Development of the Modern Sector The modern sector of the African economy was developed largely by Europeans during the colonial period and geared toward the export of raw materials. Industrialization was minimal. After independence, many African governments pursued industrialization programs with varying success. Today, African nations face the challenge of expanding their economies to fulfill the needs of their people while maintaining their profitable export-oriented activities. B1 Colonial Economy The colonial economy was centered around isolated agricultural and mining centers in which foreign-financed and foreign-managed firms employed local labor to produce raw materials for export to Europe, North America, and Japan. Colonial administrations started most of the important large-scale farming and mining activities: for example, cotton growing in the irrigated Al Jaz?rah (Gezira) region of Sudan, rubber growing on plantations in Liberia, coffee growing in Côte d'Ivoire, Ethiopia, and Kenya, and copper mining in Zambia. For a variety of reasons, colonial economies did not focus on developing industry to produce finished goods for local consumption. First, markets for finished goods in Africa were small. Second, mineral and agricultural raw materials, for the most part, were not processed in Africa, or were only minimally processed to ease shipment to ports. Third, since African industrialization was largely initiated by European firms, it was not in the firms' interest to create competition for their own products in Europe. Fourth, in the case of some countries, both the colonial and later African governments kept the exchange rates of their currencies too high, making imported consumer goods more affordable. South Africa and Zimbabwe were two distinct exceptions to this general lack of industrialization. South Africa had been administered by settlers of European descent since the early 20th century. The size and technical skill level of the settler population--combined with relative autonomy from colonial powers--supported greater economic development, making it possible for industrialization to succeed. In the case of the colony of Rhodesia (what is now Zimbabwe), the white minority regime faced world sanctions for its illegal takeover of the government in 1965, and was forced to embark on homegrown industrial development to meet its own domestic needs. At independence in 1980, Zimbabwe had one of the most developed economies on the continent, second only to South Africa. Colonial export-oriented industries did make some positive marks on the African economic landscape. They introduced important innovations in transportation, banking, marketing, trade, and many commercial services. They also led to improvements in government administration, agricultural practices, health care, and education. However, these innovations were not intended to modernize Africa as a whole. Instead, they were primarily concentrated in and around a small number of principal ports and trade centers, which usually also served as colonial capitals. This unbalanced system gave rise to tremendous disparities between developed urban centers and the rural sector. B2 Postcolonial Development From 1960 to 1980 most newly independent African countries launched ambitious development plans to lift the standard of living of their peoples, who had suffered years of colonial misrule and exploitation. Development projects were launched to spur economic development by promoting manufacturing and other industries. One major goal of industrialization was for a nation to spend less on imports by producing the consumer goods that formerly had to be imported (such as textiles, tires, chemicals, fertilizers, paper, glass, ceramics, and electrical equipment). This strategy, known as import substitution, faltered in the 1960s because of the inability of new African manufacturers to produce consumer goods efficiently. New factories required imported machinery and other costly goods to sustain production. The high costs made local manufacturers inefficient and incapable of competing with foreign manufactured products. The efforts were also hampered by the relatively low demand for consumer goods by Africa's small markets. The other major goal of industrialization was to increase earnings by promoting exports. Toward this end, foreign development agencies encouraged the colonial practice of developing export-oriented centers of raw material production. African governments therefore not only continued to protect the isolated mining and agricultural developments from the colonial era, but also helped create new ones. The guiding theory, borrowed from basic Western economic ideas, was that the high incomes generated in the developed areas would spill over into the local economy in the form of higher demand for locally produced goods and services. In response, the local people would not only spend more themselves, but would also invest both in new industrial developments and in building the roads, schools, health facilities, and so forth needed to support the expanding economic activity. All of this, in theory, would lead to still further increases in income. Meanwhile, national export earnings would be used to fund further development projects in agriculture and industry. Thus, the developed area would initiate a cycle of rising incomes, consumption, and investment, culminating in a takeoff in industrialization and modernization. The reality was quite different. First, the export-promotion strategy was crippled by declining world prices for African raw materials. Second, what wealth was generated in the developed areas was often expatriated to foreign investors, siphoned off by national governments, or spent on ostentatious public works and imported consumer goods for urban residents. The promised economic spillover effects were minimal, except in oil-producing countries such as Libya, Gabon, and Nigeria, and in a few other countries such as South Africa, Zimbabwe, and Kenya, which received significant amounts of foreign investment in industry. Furthermore, the geographic distribution of development remained as limited as in the years when Africa was under colonial rule. Export production and other manufacturing activities were concentrated in isolated rural areas and in a few port cities or other transportation hubs. Colonial-era transportation networks and marketing systems remained in place, and continued to favor these locations. The result was a widening economic disparity between centers of development and outlying areas. Innovations in modern technology and know-how developed in cities like Dakar, Senegal; Abidjan, Côte d'Ivoire; Lagos, Nigeria; Addis Ababa, Ethiopia; Nairobi, Kenya; Lusaka, Zambia; and Harare, Zimbabwe, and city dwellers saw their living standards improve. At the same time, outlying areas increasingly faced poverty. African governments sought to improve traditional subsistence agriculture either by promoting the use of modern farming equipment, fertilizers, and pesticides; or by forming collective farms for subsistence farmers to share. These measures were somewhat successful in improving the quality of life of some rural populations, but failed to transform Africa's traditional subsistence mode of production. Despite these challenges, African industry has made important strides since the 1970s. In this period, many African governments developed more effective import substitution strategies by more closely analyzing their internal and external markets and producing goods that were easiest to produce, given their countries' resources. There was measurable success in many sectors, especially in consumer products, though not all import substitution schemes worked out. C Labor Only 52 percent of the African population is between the ages of 15 and 64, the age range that is conventionally considered to be working age. About 45 percent are children under 15 years of age, while 3 percent are 65 years or older. Africa has the highest dependency ratio--the proportion of the total population that needs to be supported by the working-age group--of any continent. This does not mean that children under 15 years of age do not work. In rural areas, children, especially girls, start work at 5 or 6 years of age. The child labor pool is shrinking, however, as opportunities for universal elementary education expand. Only a small portion of Africa's labor force--mainly males--has formal wage-paying jobs in the cities or in the mining and plantation sectors. Most of the labor force is employed in subsistence production in rural areas or in the informal sector of the urban economy. The latter often involves women and children, and includes petty trade and other urban services such as cleaning, repairs, manual labor, and handicrafts. The lowest earnings come from the rural subsistence occupations, which generally require basic traditional skills. Rural cottage industry is usually more profitable, but these occupations require higher skill levels and typically necessitate long apprenticeships. During the colonial period, the creation of a small number of more lucrative jobs in mining or plantation agriculture caused subsistence occupations to lose their respectability as routes to well-being. Eventually they were stigmatized as 'primitive' by a growing number of young men, who went off to big cities in search of better-paying jobs. Africa's major cities remain magnets for the rural labor force, which perceives these areas as centers of opportunity. The rise in the number of rural-urban migrants has contributed to wild growth, high unemployment, and overextended social services in African cities. In most countries in Africa, the major cities drain most of the national resources for modernization, leaving little to be shared with the rural population. At the same time, the unrestrained rural-urban migration has grave consequences for the food-producing areas that are losing significant numbers of able-bodied workers to the cities. D Economic Activities Despite the expansion of industry and services and the growing economic importance of these activities, in almost all African countries agriculture continues to be the most important economic activity. Agriculture makes up about one-sixth of Africa's total gross domestic product (GDP), while industry makes up about one-third, and services about half. D1 Agriculture Despite being the most agriculture-based continent in the world, Africa does not produce enough food to feed its people. There are a variety of reasons for this problem, notably Africa's high rate of population growth, the loss of farm labor due to widespread movement of workers from rural areas to urban areas, the economic priority given to the production of export crops, and a general lack of adequate investment in modern agricultural technology. Many African countries must import food staples and require food aid. Africa's most important export crops are coffee, cotton, cacao beans (cocoa beans), peanuts, oil palms, tobacco, cloves, and sisal. Major food subsistence crops include maize, rice, millet, and cassava. Cattle, sheep, and goats are also important sources of protein. The continent's different climatic zones have their own opportunities and limitations for agricultural development (see the Climatic Zones section of this article). The lack of modern agricultural technology among African farmers renders them powerless to overcome the climatic limitations of their regions. D1a Tropical Wet Zone In the tropical wet zone, occurring close to the equator in West and Central Africa and eastern Madagascar, dense natural vegetation requires periodic clearing and burning to obtain plots for cultivation. Both small-scale and plantation agriculture are practiced in the zone, but small-scale production predominates for almost all export crops as well as food crops. Major export crops include coffee, oil palms, and cacao, and important subsistence food crops include cassava, yams, okra, plantains, bananas, and legumes. In most areas, farmers grow both export crops and subsistence food crops. Most of Africa's exports of coffee, cacao, and oil palm products come from small-scale producers in this region. In some areas of Liberia, Côte d'Ivoire, Ghana, and Nigeria, plantations using modern mechanical equipment and artificial fertilizers have been established. The most notable example is the extensive Firestone rubber plantation of Liberia, which produces most of the country's rubber crop. Other major successful commercial undertakings include coffee growing in Côte d'Ivoire and cacao production in Ghana. D1b Tropical Summer Rainfall and Highland Zones The tropical summer rainfall and highland zones are less agriculturally viable than the tropical wet zone. In these regions--covering a huge area that includes much of the tropical savanna land of West and southern Africa, as well as the East African highlands and most of Madagascar--rainfall is lower and less reliable, and the soil is often difficult to work by hand. This forces subsistence producers to limit cultivation to isolated areas of relatively high fertility, such as river valleys with rich, easily worked sedimentary deposits. Legumes and grains such as millet, sorghum, maize, and wheat dominate subsistence agriculture. Large-scale plantations are uncommon, except in wetter plateaus of Zimbabwe, South Africa, Kenya, Ethiopia, and Tanzania, which support plantations of tea, coffee, tobacco, pyrethrum, and fruit. Both crop cultivation and livestock herding are limited by the prevalence of the tsetse fly, which spreads sleeping sickness. The tsetse continues to prevent settlement and farming in potentially valuable areas, especially wetter and riverside savanna areas. The tsetse is less common in the open and drier savanna, and these areas are used for the raising of cattle, sheep, and goats. Ethiopia, Zimbabwe, and Botswana export substantial quantities of livestock products, including live animals. D1c Semiarid and Arid Zones In West and north central Africa, the semiarid zone known as the Sahel extends from northern Senegal in the west to eastern Sudan in the east. Other semiarid areas are found in east central and southern Africa. Rainfall is sparse and unreliable and falls at best only in a short rainy season in the summer. Population settlement is very sparse and migratory herding is still important as a source of food and of exportable hides and skins. Subsistence farming in the semiarid zone is carried out on small plots. The zone's short growing season limits farmers to low-yield crops like millet and cowpeas. More productive farming of crops such as cotton, rice, and peanuts occurs in the valleys of the Nile, Niger, and Sénégal rivers. The fertility of some areas of the Sahel has declined due to erosion, population growth, and centuries of farming. Disastrous droughts caused famines in the region in the 1970s and 1980s. To cope with these challenges, the countries of the Sahel region have required considerable international assistance in the form of food aid and rural development ventures. The arid Sahara occupies all of North Africa except for the coastal fringes of Morocco, Algeria, and Tunisia. In southern Africa, the arid zone is limited to the Namib Desert. Very little farming takes place in these deserts. Until the discovery of oil in the 20th century, the Saharan economy depended on migratory herding, sedentary settlements raising date palms and some millet around a few oases, and long-distance commerce by camel caravans. Lacking the extensive petroleum deposits of other North African countries, Egypt built the Asw?n High Dam on the Nile from 1960 to 1971 in order to expand irrigation for agriculture. Cotton is the chief export crop along the Nile, and lentils and many cereal crops such as rice, maize, wheat, and millet are also raised. D1d Mediterranean Zone The Mediterranean zone--found only at the northern and southern extremities of the continent, on the coasts of Morocco, Algeria, Tunisia, and South Africa--has soils and topography suitable for the cultivation of vineyards and orchards of citrus and olive trees. The farms in this zone are among the most prosperous and modern in Africa, and agriculture here is often combined with food-processing activities such as wine making and fruit preserving. Cereals such as wheat are important, and livestock, particularly sheep, are also raised. Exports of farm products are very profitable in the Mediterranean zone, especially for Morocco, Tunisia, and South Africa. D1e Land Use and Ownership Before Africa was colonized, Africans farmed or herded with little or no regard for land ownership. Land was shared by clans, communities, or ethnic groups, and was often shared between groups as well. One group may have farmed a piece of land for part of the year, while another group grazed livestock on the land while it lay fallow (unfarmed) the rest of the year. The concept of exclusive land ownership was introduced by colonists, who, in many areas, seized the best farmland in order to grow export crops. Less fertile areas were left for indigenous Africans, who farmed them in small, fragmented plots. This process was fostered by many independent African governments, which seized further communal farmland for private, corporate, or governmental use. Eventually, smallholders' plots became increasingly subdivided into smaller fragments in order to provide at least some land to each of the growing generation of village families. Fallow periods, essential to maintaining the fertility of the soil, have been steadily reduced because all available land has been brought into cultivation. In addition, many smallholder farmers, unsure about the future of their farms in light of land seizures, began to favor short-term crops. In doing so, they abandoned traditional practices of crop rotation and intercropping--planting soil-depleting cereal crops and soil-restoring legume crops on the same land, either one after another or at the same time. Many farms became infertile, further reducing the amount of land available to smallholders. Coupled with recurrent drought, these conditions have brought serious food shortages to much of sub-Saharan Africa. Many African governments have consequently faced the need for land reform. In some countries, land reform measures and rural development schemes initiated soon after independence gave smallholder farmers ownership of or leasehold rights to the small parcels of land they were already working as tenant farmers. Many African governments have resorted to nationalization of land assets with the presumed claim of better land distribution among the landless. In some countries, such as Ethiopia, land reform has been manipulated for political purposes, and mismanagement and corruption has harmed agricultural production. In other countries, such as Zimbabwe, the best lands remained in the hands of European settlers and were not redistributed after independence. D1f Agricultural Output There were encouraging trends for African agriculture in the early 21st century. With the exception of countries that faced political turmoil in the 1990s, much of Africa--including countries with large populations, such as Nigeria, Ghana, Tanzania, and Zimbabwe--showed impressive growth in agricultural production. Profits from agriculture rose significantly in the 1990s and outperformed the previous decade. African policymakers remain concerned about population growth outpacing the growth of food production, but current trends point toward a more optimistic scenario for Africa's food supply. D2 Forestry Although about one-fifth of the continent is covered by forest, there is relatively little forest industry in Africa. Most felled trees are cut down to clear land for farms or, to a lesser extent, to supply fuelwood. The most desirable timber trees are mahogany, obeche, iroko, and other tropical hardwoods. Tropical forests rarely offer dense stands of a single species, however, inhibiting massive logging operations. Selective cutting is very expensive, especially in the interior where transport costs become prohibitive. In 2006 African countries exported $4 billion of forest products. The largest exporters were South Africa, Cameroon, Gabon, Côte d'Ivoire, and Ghana. Countries with greater levels of industrialization were more likely to process timber into sawnwood for export, which is typically more profitable than exporting uncut timber. For example, South Africa, Côte d'Ivoire, and Ghana cut or otherwise processed almost all of their exported forest products, while Gabon, Equatorial Guinea, and Liberia exported almost all of their forest products unprocessed. D3 Fishing Fish is not a major staple food in the savanna and highland zones of Africa, where there is a relative abundance of livestock as a source of protein. However, in the tropical forest margins of the West African coast, fish is a crucial source of protein and, in dried form, a common condiment. Principal grounds for marine fish such as tuna, sardines, and hake are found off the West African coast from Morocco to Senegal, and from Angola and Namibia. The Nile, Niger, Congo, and Sénégal rivers and Lakes Victoria, Tanganyika, Malawi, and Chad are major sources of freshwater fish. The most common freshwater catch is the Nile perch. In 1999 African fishers caught a total of 6.3 million metric tons of fish, of which 3.8 million metric tons were marine fish. Morocco, Egypt, South Africa, Ghana, and Nigeria were the top African countries in total fish catch; and Morocco, Namibia, South Africa, Senegal, and Libya exported the most fish. Morocco is also the leader in fish-processing industries, producing more canned fish, fish oil, and fish meal than any other African country. D4 Mining Africa plays a very important role in the global mineral economy, producing about three-quarters of the world's cobalt; half of the global supply of platinum, chromium, and diamonds; approximately one-third of all gold, manganese, and uranium; one-fifth of all bauxite; and one-tenth of the world's petroleum. Minerals account for at least half of export earnings in 12 African countries, and 90 percent or more of exports in Angola, Nigeria, Algeria, Libya, and Zambia. The countries of the Sahel and East Africa, where mineral production is unimportant, are notable exceptions. North Africa is one of the world's major centers of oil production, and Libya, Algeria, and Egypt are among Africa's top producers of crude petroleum. Algeria has vast reserves of natural gas as well. North Africa is also rich in phosphate deposits and production, Morocco being a leader in world output. Of lesser significance in the region are coal, iron ore, uranium, platinum, lead, zinc, and cobalt. West and Central Africa also contain significant oil reserves. Nigeria is Africa's top petroleum producer, and Angola, Gabon, and the Republic of the Congo are other important oil-producing countries. West and Central Africa also possess some of the world's most significant sources of cobalt, manganese, potash, bauxite, and copper. Guinea has about one-third of the world's reserves of bauxite, the commercial source of aluminum. Other minerals of economic significance are iron ore, gold, diamonds, tin, uranium, phosphate, columbite, and titanium. Southern Africa is one of the world's richest sources of gold, diamonds, and several rare metals. South Africa has the largest and most diverse mineral economy, and is a leading producer of gold and of uncut diamonds. Zimbabwe is also an important producer of gold, and Botswana and Namibia are important producers of diamonds. Other important minerals produced in southern Africa include chromium, cobalt, antimony, uranium, lithium, nickel, manganese, asbestos, platinum, titanium, and vanadium. The economies of African countries that are heavily dependent on one principal mineral export are seriously affected by price declines in the world market. Recent decades have seen destabilizing shifts in the price of Zambia's copper, Guinea's bauxite, and Togo's phosphate. D5 Manufacturing In general, manufacturing is an underdeveloped activity in Africa. Countries with more developed manufacturing sectors include South Africa, Zimbabwe, Egypt, Algeria, Burkina Faso, and Côte d'Ivoire. Much of Africa's modern industrial activity involves the processing of raw materials. Processed foods are largely consumed by Africa's expanding urban populations, while raw materials such as minerals, petroleum, and timber are processed almost entirely for export. The bulk of the rest of Africa's manufacturing output consists of consumer goods such as textiles, footwear, beverages, and soap. The technology used in manufacturing ranges from rudimentary tools used in small-scale cottage industries to large-scale factories. Although its impact on the national economy is frequently underestimated, the cottage industry sector of the economy produces significant amounts of goods both for local consumption and for the tourist trade. Textile and footwear plants, on the other hand, can be sizable, often requiring modern machinery. Heavy industry--such as the production of metal, cars, motorcycles, bicycles, and household appliances--is limited to a few countries, notably South Africa, Egypt, Algeria, Zimbabwe, Nigeria, and Côte d'Ivoire. Almost all consumer goods produced in Africa are sold and used within Africa rather than being exported. African manufacturing grew in the 1960s and 1970s, but declined in some countries--including Nigeria, Ethiopia, Ghana, Tanzania, Zambia, and Zimbabwe--in the 1980s and 1990s for several reasons. First, many oil-rich countries like Nigeria relied too heavily on extracting and exporting petroleum and neglected their manufacturing sector. Second, war and political unrest disrupted development efforts and caused the role of manufacturing to decline in formerly robust economies like those of Nigeria, Sudan, Ethiopia, and Zimbabwe. The development of African manufacturing has also been hindered by a general lack of investment capital, as well as by misguided economic strategies and corruption. In addition, multinational corporations have tended to discourage African manufacturing, seeking instead to trade their manufactured goods for African raw materials. Africa also has an inherently small market for consumer goods due to its mostly rural, subsistence-oriented population. D6 Services In African countries, on average, the service sector makes up about one-half of the GDP, but employs only about one-third of the labor force. Social services such as education and health services make up the bulk of the African service sector. Formal schooling and modern public health care expanded across much of Africa in the second half of the 20th century. African governments have built countless schools, clinics, and other basic service facilities needed to improve their people's living standards. Commercial services are less developed in much of Africa. The principal types of commercial services include transport, communication, tourism, banking, insurance, and import-export agencies. Countries with mineral wealth, such as South Africa and Botswana, or developed tourist industries, such as Kenya, have a much higher level of these commercial services than more agricultural countries like Ethiopia and Ghana. Most commercial service institutions and infrastructures remain concentrated in areas of modern development and major urban centers. The African service sector has several general features, characteristic of less developed areas, that combine to limit its impact on national economies. First, the government is often the most important investor and employer, especially in the social services sector (which includes government, civil services, and defense). Second, the most lucrative aspects of the commercial service sector--banking, insurance, tourism, import-export, communication, and transport--are usually owned, controlled, or operated by foreign companies. Third, many of the commercial services required by African smallholder farmers and cottage industry operators--such as transportation and credit services--are provided in the informal market, and are therefore undocumented. As more service institutions become locally and privately owned, and as they extend their reach to small-scale producers, they will benefit African countries' economies to a greater degree. D7 Energy Wood from trees and shrubs is still the most important source of domestic fuel in Africa. Use of coal and petroleum is limited to urban centers, modern factories, and power plants. In 2003, 79 percent of the electricity generated in Africa was produced by burning coal and other fossil fuels. The most promising source of energy in Africa is hydroelectric power generation. The continent's many large rivers give it a vast hydropower potential that has barely been tapped. Several major installations have been constructed since 1960, including the Asw?n High Dam on the Nile River, the Akosombo Dam on the Volta River, and the Kariba Dam and Cabora Bassa Dam on the Zambezi River. In 2003 African hydroelectric plants produced 18 percent of the electricity generated in Africa. D8 Transportation Transportation in most of Africa is rudimentary. Most people walk to markets, schools, and health facilities, often carrying needed items on their heads or shoulders. However, bicycles and animal-drawn carts are increasingly available in rural communities. The use of motorized vehicles is mostly limited to cities and intercity traffic by buses and trucks. Throughout the continent, smallholder farmers are unlikely to afford motor vehicles. Bus and train travel is within the means of most people and they are used especially for long-distance travel. The quality and connectivity of African roads and railroads remain poor: Most roads are made of dirt or gravel, and good quality all-weather roads are limited. Colonial rulers laid railroad tracks to connect ports to export-producing areas in the interior, and these networks have been largely unexpanded since independence. Few roads and tracks cross international boundaries in Africa. The poor condition and disjointedness of the road and rail networks have hindered African economic development. South Africa, with higher-quality roads and a greater degree of road and rail connectivity, is a notable exception. Many African countries operate national airlines. South Africa, Egypt, Ethiopia, Kenya, Nigeria, and Ghana have well-developed airline systems for domestic, international, and intercontinental flights. E World Trade And Debt As was the case during colonial rule, Africa's role in the world economy remains to produce raw materials for use in developed nations. Whatever economic development has occurred in African countries since the end of colonial rule has reinforced this pattern. Investment by international corporations and most foreign governments has concentrated on expanding production of exportable mineral and agricultural raw materials. The emphasis on exports has left inadequate resources for developing domestic industry or changing the traditional, underdeveloped system of African smallholder food production. Neglecting their food-producing sectors has led African countries to increase their dependence on raw-material exports and has required many to import food to feed its people. The continent's trade position has faced further challenges since the 1960s. The prices of manufactured goods and fuels imported by African countries increased substantially, while the prices of almost all products of African mines and farms declined or fluctuated. This downturn meant that African countries not only had to make do with fewer needed imports, but they also had to go into international debt to meet their financial obligations. Oil-exporting countries were able to avoid this pitfall for a time, but they too were beaten down by the collapse of world oil prices in the 1980s and 1990s. Africa has also been put at a disadvantage by the protectionist trade policies of industrialized countries, which admit unprocessed raw materials tax-free but impose substantial tariffs on imported products made from the raw materials. As a consequence of their internationally disadvantaged status, nearly all African countries have had to borrow money from foreign lenders to cover the difference between their export earnings and their spending for imports. The amount of accumulated external debt owed by sub-Saharan African countries has risen from less than $6 billion in 1970, to $80 billion in 1985, to $230 billion in 1999. Interest payments to foreign creditors siphon away precious foreign exchange earnings. Such pressures on export earnings have led African governments to make stringent cuts in imports through high tariffs and outright prohibitions. The Economy section of this article was contributed by Assefa Mehretu. V HISTORY At some point between 130,000 and 90,000 years ago the first true human beings, Homo sapiens, evolved in eastern and southern Africa. These Stone Age humans had the same capacity for thought as modern human beings. They were capable of making tools such as hooks and needles made of bone, and precise stone blades. These stone blades could be used as scrapers and hand-knives, or attached to poles and sticks for use as spears or arrows. By 90,000 years ago Homo sapiens had begun to move out of Africa into the Middle East, Europe, Central Asia, and beyond. All modern human beings are descended from these original African ancestors. A Early Africans By 40,000 years ago people could be found hunting and gathering food across most of the regions of Africa. Populations in different regions employed various technological developments in adapting to their different environments and climates. The most notable adaptations occurred in response to major climate changes. A1 Spread of Languages and Cultures Between 16,000 and 13,000 BC the climate of much of Africa was considerably drier than it is today. The Sahara expanded north and south at the expense of grassy steppe lands and woodland savanna, and the area of equatorial rain forest shrank. This put pressure upon human hunter-gatherer populations to improve their techniques and to more intensively use locally available food resources. Those who adapted most successfully spread their techniques, cultures, and languages beyond their home areas, while absorbing or influencing other populations. This period gave birth to the four great language families of Africa--Afro-Asiatic, Nilo-Saharan, NigerCongo, and Khoisan--from which all modern African languages are descended. From Eritrea and the Red Sea Hills to the northern borders of Sudan, speakers of Afro-Asiatic languages specialized in collecting the seeds of wild grasses, which were ground into flour. Over subsequent millennia their descendants spread their languages and cultures northward into Egypt and westward over the whole of North Africa. In the middle Nile region of central Sudan the speakers of Nilo-Saharan languages specialized in hunting large antelope, including the wild ancestors of Saharan cattle. Eventually these people also spread, moving south into East Africa and west across the southern Sahara. In the savanna woodlands of West Africa, speakers of early Niger-Congo languages hunted with bow and arrow, fished with hook and line, and intensively collected the West African yam. Their languages and cultures eventually spread across the whole of West and Central Africa, and later, even to the southern reaches of the continent. In East Africa, from what is now Kenya to northern Zambia, speakers of ancestral Khoisan languages made the most successful adaptations of this period. They developed a wide range of small, finely honed stone tools for hunting and many other purposes. Their adaptable tools and tool-making skills enabled the Khoisan to become excellent hunters and to spread throughout southern Africa, and partly explain why, through thousands of years of further climate change, they felt no need to domesticate animals and plants like their northern neighbors. A2 Origins of Cultivation and Herding Between 11,000 and 3500 BC Africa experienced a wet climatic phase, which reached its peak between 9000 and 6000 BC. The Sahara became a grassland steppe surrounded by savanna woodlands, perennial rivers flowed from its mountain ranges, and Lake Chad expanded into a vast inland sea. The environmental changes opened huge new opportunities for Africa's human populations. Farming originated in this period with the domestication of African plants and animals. The Nilo-Saharan speakers of central Sudan adopted the grain-collection practice of their Afro-Asiatic-speaking neighbors. They applied it to wild sorghum, a tropical grass, which they domesticated and cultivated by 8000 BC. By this time, they had also invented techniques for making pottery, which was used to collect and store food and water. In the same period, Nilo-Saharan speakers domesticated wild cattle in and around the Nile Valley. Between 7000 and 5000 BC they also domesticated pearl millet, gourds, melons, and beans, and spread their farming and herding practices westward across the southern Sahara. By this time, northern Afro-Asiatic speakers had taken wild seed collecting practices into Egypt, where they domesticated donkeys and pigs. They also spread into the Middle East, where tropical grasses would not grow. Instead, they learned to domesticate wheat and barley, and cultivation of these grains spread back westward through the Mediterranean regions of North Africa. Meanwhile, Cushitic speakers (an Afro-Asiatic subgroup) spread herding and grain cultivation throughout the Horn of Africa and into the central plains of East Africa. In the valleys of the Ethiopian Highlands, the indigenous crops teff (a grain) and enset (a banana-like fruit) were also domesticated. Niger-Congo speakers in West Africa domesticated the yam and planted it in the expanded zone of savanna woodland by about 8000 BC. By 5000 BC their domesticated crops also included oil palm, raffia palm, peas, groundnuts, and kola nut, and they had also domesticated the guinea fowl. The domestication of West African rice, in and around the inland delta of the Niger, occurred slightly later, during a drier period after 3000 BC. By that time West Africans had developed polished stone axes for clearing woodland and were penetrating the rain forests of West Africa and the Congo Basin to the southeast. Another important feature of the wet climatic phase was the development of fishing cultures around the numerous expanded lakes and rivers. From Lake Chad to the upper Nile and south to Lake Turkana and the Great Rift Valley in East Africa, fishers gathered in large settlements and traded dried fish for grain and other products from their neighbors. B Ancient Nile Valley States By 3500 BC the favorable wet phase was coming to an end and the Saharan steppe again gave way to full desert. As the desert expanded, herders and cultivators concentrated in areas of perennial water sources, notably the Nile Valley. In what is now northern Sudan and southern Egypt, the north-flowing Nile forms a great Sshaped curve and passes through six cataracts (rapids or waterfalls), which are numbered from north to south. In this area, known as Nubia, the concentration of settlements between the first and fourth cataracts prompted the clearing of riverside vegetation and exposure of the fertile floodplain. Large-scale projects such as this required communal labor and, consequently, the development of political and religious authority capable of commanding large workforces. Clan chiefs became kings, with each king acting as the guardian of his kingdom's god. B1 Ancient Egypt Nubian concepts of kingship and religion spread northward to the Nile Delta region (known as Lower Egypt) as the desert encroached ever closer to the river. The navigability of the river from the delta to the first cataract allowed for easy communication and the expansion of political authority. Kingdoms along the Egyptian Nile merged until there were only two: Upper Egypt and Lower Egypt. In about 3100 BC the two kingdoms were united by Narmer, king of Upper Egypt, who thus founded the earliest dynasty of Ancient Egypt. The old Nubian gods of the individual kingdoms became regional deities in a new polytheistic religion, and the creation of this regionally diverse religion helped cement the unification. Egyptian unity prevailed for about 900 years. The first centuries saw a strengthening of central authority until, by the time of the Third Dynasty (about 2649 to 2575 BC), the king himself was recognized as a god. Egypt then entered the era referred to as the Old Kingdom (about 2575 to 2134 BC). Kingdom, Egyptians began constructing great burial pyramids for their kings. The Great Pyramid of Giza was built in about 2500 of the Fourth Dynasty (about 2575 to 2467 BC), BC Around the dawn of the Old as a tomb for Khufu, the second king and is the only one of the Seven Wonders of the World that survives intact today. Its construction required the mobilization of a huge, rotating labor force. The scope of manpower involved may have been the reason why the pyramids of Khufu's successors were never quite as big. Grand pyramid building ceased by the end of the Sixth Dynasty (about 2323 to 2151 BC). Farm labor by peasants, who made up the vast majority of the Egyptian population, formed the economic basis of Ancient Egypt. The annual flooding of the Nile renewed the soils of the valley with fertile silts carried down from the far-off Ethiopian Highlands. As the annual flood receded, the farmers moved back onto the floodplain, digging irrigation canals and planting their crops in the rejuvenated soil. They grew wheat, barley, flax, vegetables, and fruit. Peasants also herded cattle and goats, fished for Nile perch, and hunted wild birds in the marshes. Every aspect of the peasants' labor was overseen by government scribes and tax collectors, who developed hieroglyphs, possibly the earliest form of writing in the world. All agricultural surplus went to the state to support the king in luxury and to feed and clothe his huge army of government servants, artists, artisans, builders of pyramids and temples, priests, and guardians of religious shrines. During most of the Old Kingdom, trade remained a monopoly of the state. During the Sixth Dynasty, however, wealth became more widespread among regional princes, merchants, and priests. Around 2200 BC northeast Africa experienced several decades of cooler, drier climate. The Nile failed to flood and Egypt suffered a devastating famine. Central authority collapsed and regional princes asserted their independence. In about 2040 BC the kings of Thebes in Upper Egypt reestablished Egyptian unity and Egypt entered what is known as the Middle Kingdom (about 2040 to 1640 BC). In this period, Egyptian trade expanded down the Red Sea coast of Africa. This time, however, the trade was run by professional merchants, and the central government taxed the trade instead of running it as a royal monopoly. Middle Kingdom kings revived pyramid building, though on a much smaller scale. In about 1640 BC Middle Kingdom unity was destroyed by an invasion of the Nile Delta region by invaders from the Middle East known as Hyksos. These foreigners, who introduced horses to Egypt, established a rival dynasty in the delta. In about 1550 Dynasty (about 1550 to 1307 BC). BC Ahmose I, king of Upper Egypt, defeated the Hyksos and founded the 18th In doing so, he reestablished Egyptian unity and Egypt entered an era called the New Kingdom (about 1550 to 1070 BC). For the first time, Egyptian kings maintained a standing army, and military conquest was used to build an Egyptian empire from Palestine and Syria in the north to the fourth cataract of the Nile, the heart of Nubia, in the south. Pyramid building was not revived, but massive statues and temples were built. Kings, now known as pharaohs, were buried in elaborately decorated tombs cut into solid rock in the Valley of the Kings across the river from the royal capital of Thebes. Egypt's power declined during the 20th Dynasty (about 1196 to 1070 BC). The New Kingdom empire broke apart as Palestine and Nubia reclaimed their independence. There followed a succession of foreign invasions and rebellions by Libyan mercenaries. From this point on, native Egyptian dynasties were interspersed by Nubian, Assyrian, and Persian ones, until the last Egyptian dynasty fell to Greece in 332 B2 BC. Nubian Kingdoms By the time of the unification of Egypt in 3100 BC, several Nubian kingdoms had already been established along the middle Nile between the first and fourth cataracts. After an Egyptian invasion of Nubia as far as the second cataract in about 1900 BC, the Nubian kingdoms formed a loose unity, centered on the city of Kerma, just south of the third cataract. Little is known about this kingdom until it was brought within the Egyptian New Kingdom empire about 1500 As Egyptian control weakened after 1100 BC, BC. Nubia reasserted its independence and became known as Kush. A new capital and religious center was established at Napata, near the fourth cataract, and Kushite culture flourished. Kush's agricultural economy was based on cattle herding and cultivation of sorghum and millet. Through payments from subject provinces and trade in ivory, skins, and ebony from the south, the kings of Kush grew wealthy and powerful. In about 770 invaded Egypt and established what is known as the 25th Dynasty (about 770 to 657 The Kushites were ousted from Egypt in the 7th century BC BC) BC). they by an Assyrian invasion from the Middle East. The Assyrians wielded weapons of iron, a metal until that time unknown in North Africa. The Kushites withdrew to Napata, and again farther south to Meroë, following an Egyptian invasion in 593 the Kushite capital until 300 BC at Thebes. BC (although Napata would remain At Meroë, between the fifth and sixth cataracts, the Nubians would found a new kingdom based in large part upon the new technology of ironworking (see the Meroë section of this article). C Dawn of the Iron Age The first metal worked in Africa was copper, smelted and forged in Egypt before its unification in 3100 Egypt until the 17th century BC, BC. Copper and stone remained the main tool-making materials in when the Hyksos invasion from the Middle East brought bronze, a harder alloy, to North Africa. During Egypt's New Kingdom, gold was forged into jewelry and elaborate furniture to decorate the pharaohs' palaces and tombs. Far to the west of Egypt, in the Aïr Mountains of what is now Niger, copper working was independently invented some time after 3000 Songhai. By 1500 BC BC. These early metalworkers probably spoke a Nilo-Saharan language, perhaps ancestral to modern their copper-working techniques and furnaces were well developed and the technology had spread to other copper-bearing areas of the southern Sahara. Iron is a much harder metal to smelt than copper, requiring larger quantities of charcoal and much higher temperatures. Its invention, therefore, required considerable expertise in furnace building. While the knowledge of ironworking was first brought to northeast Africa from the Middle East after 670 BC, the techniques had been independently invented in sub-Saharan Africa some 300 years earlier. Presumably building upon furnace techniques developed for the smelting of copper, metalworkers were smelting iron in Chad and the Great Lakes region (an area in East Africa between and around Lakes Victoria and Tanganyika) by 1000 BC. From these centers of development, ironworking spread among the agricultural peoples of West, Central, and East Africa, reaching southern Africa in the early centuries C1 AD. Development of Farming Communities in West Africa The increasing use of iron tools and weapons helped West Africans clear woodland for cultivation and improved hunting efficiency. This accelerated the development and spread of farming communities. In the inland delta of the Niger River--where the river divides and spreads into a complex pattern of waterways--clusters of villages formed into larger settlements. Many of these Mande-speaking villagers specialized in the production of dried fish, rice, or cotton. Producing far more than they needed for themselves, they traded their surplus with their neighbors at large central markets. By about 250 BC Djenné, in present-day southern Mali, was perhaps the largest of these commercial centers. Rice growing spread to the tidal estuaries of what is now Guinea, Sierra Leone, and Liberia. In these areas local farmers developed special water-control techniques that used tidal salt water to clear the land of weeds and fresh water from rivers to irrigate the rice crop. Centuries later, slaves taken from this region would introduce similar techniques to the plantations of South Carolina in what is now the United States. Throughout the Niger-Congo societies of West Africa, craftspeople specialized in wood carving, producing dugout canoes and three-legged stools, as well as masks for use in festivals and religions rituals. A thriving, ironworking community, referred to as the Nok culture, established itself on the Jos Plateau of central Nigeria by 500 BC. Nok craftsmen combined carving and pottery-making skills in the production of finely sculpted terracotta clay heads. C2 Bantu Migration By 2000 BC Bantu-speaking farmers of the Niger-Congo culture had begun to migrate from what is now Cameroon and eastern Nigeria into the forest regions of the Congo River Basin. Traveling in dugout canoes along the region's numerous waterways, they established riverside settlements and supplemented yam and oil palm farming with hunting and fishing. By 1000 BC they had crossed the forests to reach the southern savanna lands of what is now Angola and reached the Great Lakes region in the east. In the Great Lakes region they adopted ironworking and learned techniques of cattle keeping and grain cultivation from their Sudanic- and Cushiticspeaking neighbors. Bantu-speaking farmers thus developed a unique and wide-ranging combination of technological skills: planting yams, sowing grain, herding livestock, working iron, and making pottery. This adaptable set of skills enabled them to spread, in a series of small movements, over most of East, Central, and southern Africa between 300 BC and AD 300. In the process, they interacted with and absorbed existing, mostly Khoisan, populations. The only region the Bantu did not penetrate was the far southwestern corner of Africa, which was too dry for their agricultural practices. C3 Meroë By the 3rd century BC the middle Nile Valley had a long history of agricultural settlement and political kingdoms. The kingdom of Kush formally moved its capital southward from Napata to Meroë in about 300 BC. In this island of savanna woodland between the 'A?barah and Nile rivers the ruling elite built a powerful kingdom. The wetter climate of this region allowed the cultivation of tropical cereals, sorghum, and millet. With plentiful iron ore and wood for charcoal, the kingdom of Meroë became a major center for the production of iron. Iron spears and arrows helped the kingdom defend itself against any threat from Egypt and aided hunting as well. Meroë was also in an advantageous position for trade. With access to the ivory, ebony, and animal furs of the Upper Nile, Meroë's traders were well positioned to trade with Egypt to the north and with Red Sea ports to the east. At first, the culture of Meroë was strongly influenced by that of Egypt, but the kingdom soon evolved its own distinctive culture, language, and writing. Although their religion retained many of the Egyptian gods, they developed other gods with different characteristics, notably the lion god, Apedemek. They also buried their kings in small pyramids, long after pyramid building had ceased in Egypt. By AD 300 Meroë was in decline. In feeding a dense population, intensive farming had worn out the land, while the widespread felling of trees for charcoal led to soil erosion. Furthermore, Meroë had lost its advantageous trading position to the rising kingdom of Aksum in the southeast. C4 Aksum The kingdom of Aksum arose on the Red Sea coast of what is now Eritrea. By 500 BC mixed coastal communities of local farmers and immigrant traders from southeast Arabia had developed their own language and system of writing. These ports grew in strength, competing with Meroë for control of Red Sea trade. By the 1st century AD the ports had united and come under the control of a kingdom with its capital at the inland city of Aksum. As Meroë declined, Aksum became a prosperous city. It was noted for its monumental stone architecture, especially its carved, multistoried, solid stone pillars called stelae. In the mid-4th century the Aksumite king Ezana converted to Christianity. The Aksumite church was affiliated with the Egyptian Coptic Church, and was also influenced by Syrian monasticism. With the spread of Islam in the 7th century, the Red Sea increasingly came under the control of an expanding Islamic state and Aksum lost much of its access to Indian Ocean trade. The kingdom disintegrated in the 10th century, but its unique, monastic church persisted as the state religion of the subsequent kingdom of Ethiopia. C5 Ethiopia Ethiopia, a Christian kingdom that developed in the Ethiopian Highlands after 800, was controlled by an aristocracy. The local Agaw peasantry owned and worked the land in the fertile valleys, but paid a tax from their produce to their governing aristocracy as well as to their local monastic church. In about 1150 an Agaw dynasty, known as the Zagwe, took over the kingship. The Ethiopian Christian Church flourished under Zagwe rule, as recorded in both manuscripts and architecture. The combination of Agaw belief in the sacred role of rock caves and the Aksumite tradition of grand stonework led to the creation of a series of unique churches carved into solid rock, many of which still survive today. The Solomonid dynasty succeeded Zagwe in the 13th century and established a monarchy and a political system that remained intact until the 20th century. D Early North Africa The Greek conquest of Egypt in 332 BC tied Egypt more closely to the fortunes of the Mediterranean world. The new ruling class adapted many aspects of Egyptian culture, but Greek became the language of administration and trade. A new capital city was built at Alexandria, which, within a few centuries, became the greatest trading center of the ancient world. The Greeks founded the Ptolemaic dynasty of Egyptian pharaohs, which persisted until the Roman Empire conquered Egypt in 31 D1 BC. Roman Africa Under Roman rule Egypt became a province of the empire and a major center of grain production for the citizens of Rome. The rest of Mediterranean North Africa was incorporated into the Roman Empire between 150 least 800 BC. BC. By the 5th century BC BC and AD 200. Carthage, on the northeast coast of what is now Tunisia, had been a Phoenician trading colony since at it rivaled Rome for control of the western Mediterranean Sea. After the century-long Punic Wars, Rome conquered Carthage in 146 The Romans named their new Tunisian province Africa. To the west lay independent Berber kingdoms of mountain herders and settled coastal farmers. The Romans called these lands Numidia (modern-day northern Algeria) and Mauretania (now northern Morocco). Initially, these regions maintained their independence and entered into trading alliances with the Romans, but by AD 200 they too had been largely incorporated into the Roman Empire. Roman North Africa provided the empire with wheat and olives, grown on coastal plantations worked by Berber slaves. The Roman Empire split in two in about 400 AD, and Rome declined in power. Carthage fell to Germanic invaders, known as the Vandals, in 439. After a period of Vandal rule, North Africa was recaptured by the Byzantine Empire (the eastern half of the Roman Empire) in 533. D2 By AD Spread of Christianity 100 Alexandria had become the most important intellectual center of the early Christian Church. From Egypt, monastic Christianity spread south to Nubia and Ethiopia, and west to Berber North Africa. In the latter region, the Berbers adapted the new religion to fit in with indigenous beliefs. Subjugated by the Roman Empire by 200, Berber Christians maintained a strong tradition of religious independence from Rome, even after the empire had adopted Christianity as the official Roman religion in the 320s. D3 Trans-Saharan Trade The Romans introduced the camel to North Africa in about 200, and in doing so unwittingly revolutionized trans-Saharan trade. North African Berbers and other residents of the central Sahara quickly adopted the use of camels, both as a source of food and as a means of transport. Where trade across the desert had formerly been sporadic, moving haltingly from oasis to oasis, it was now possible to take a camel caravan on a two-month journey directly across the Sahara. Trade and contact between the Mediterranean world and sub-Saharan West Africa flourished. Major traded commodities included horses, weapons, and textiles from the Mediterranean; gold, slaves, and animal products from West Africa; and salt mined from dried-up prehistoric lakes in the central Sahara. D4 Islam and the Arab Conquest of North Africa The religion of Islam, founded in Arabia in the early 7th century, quickly united Arabs and inspired the expansion of a great Islamic empire across the Middle East and North Africa. By 641 Muslims had conquered Egypt, where they established a new ruling class of administrators and merchants. Over the ensuing centuries, and following further Arab immigration, most of the Egyptian population converted to Islam and adopted the Arabic language, leaving the Egyptian Coptic Church as a small Christian sect. In Nubia, the Christian kingdom of Makuria managed to maintain its independence, establishing important trade connections with its newly Islamic northern neighbors. Arab penetration south and conversion of Christian Nubia to Islam did not occur until the early 14th century. The Arabs referred to North Africa west of Egypt as al-Maghreb ("the West" in Arabic). Muslims conquered Byzantine Carthage in about 700, and by 711 they overcame Berber resistance, extended their empire to Morocco, and crossed the Strait of Gibraltar to southern Spain. In the Maghreb, the Arabs were initially confined to coastal regions. Here, captured Berbers were conscripted into the Arab army and converted to Islam. Inland, among the Berbers of the mountains and desert, conversion proceeded at a slower pace. In addition, many Berber groups asserted their independence from the caliphs (the rulers of the Islamic empire) soon after being converted. Over the ensuing centuries, a number of independent Islamic Berber states rose and fell, until, in the 10th century, the Fatimid dynasty united the central Maghreb. In 969 the Fatimids conquered Egypt and declared their independence from the caliphate. D5 Egypt Under the Fatimids, Mamluks, and Ottomans The Fatimids established a new Berber aristocracy in Egypt. The main wealth of the country, as always, was derived from peasant agriculture. Fatimid rulers granted Berber aristocrats huge land estates from which they were to collect taxes from the peasants. A portion of this tax was paid to the state and the rest retained by the Berber landholder. As the Berbers settled into the role of landed elite, their former ranks in the Fatimid army were filled by legions of Turk and Mongol slave soldiers known as Mamluks. In 1171 a Kurdish military officer named Salah al-Din Yusuf ibn Ayyub, also known as Saladin, seized the Egyptian throne and founded the Ayyubid dynasty. His action was prompted by the threat to Egypt posed by Christian Crusaders from Western Europe who had seized control of much of Palestine (see Crusades). Saladin reformed the army, imported more Mamluks, and placed the land estates and the collection of taxes in the hands of successful Mamluk officers. These Mamluks became the new Egyptian aristocracy and in 1250 they seized the throne from the Ayyubids. The Mamluk dynasty ruled Egypt for the next 250 years. The Mamluk period was a time of great religious and cultural revival in the Egyptian capital of Cairo. However, in the countryside--where the vast majority of Egyptians lived--the estate holders abused their tax-collecting powers and exploited the peasantry. In 1517 the Ottoman Empire conquered Egypt and made it an Ottoman province. The Ottoman sultan appointed the pasha, or governor, of Egypt, but otherwise Ottoman Egypt was largely able to act autonomously. Under the Ottomans, Egypt's boundaries were extended south as far as the third cataract of the Nile and down the Red Sea coast as far as Eritrea. South of Egypt, a dynasty of black Muslims known as the Funj established a sultanate over the Sudanese Nile centered at Sann?r (Sennar) and extending as far south as the highlands of Ethiopia. D6 Almoravids and Almohads of Northwest Africa Across the Sahara, Islam provided the traders and herders of the remote desert oases with a common sense of brotherhood. Trans-Saharan trade expanded in response to the Islamic world's demand for West African gold for its trading currencies. Muslim Berbers making their pilgrimages to Mecca--a duty of Muslims--were exposed to the vast differences between life in the remotest Saharan oases and the realities of the wider Muslim world. Scandalized by the wealth and luxuries of urban North Africa, a small group of Sanhaja Berbers in what is now Mauritania initiated an Islamic reform movement in the mid-11th century. Known as the Almoravids, they provided the desert peoples with a new sense of unity and reformist zeal. The Almoravids built up a mass army that swept north through the western desert and conquered Morocco. After the deaths of early Almoravid leaders in the late 1050s, the southern desert regions broke away. In the 1140s another reformist movement, known as the Almohads, overthrew the Almoravids and established the Almohad empire over much of the Maghreb. In subsequent centuries the Almohad empire broke apart into three Islamic states, roughly corresponding to the modern nations of Morocco, Algeria, and Tunisia. D7 Ottoman Maghreb and Morocco In the decades following the Ottoman conquest of Egypt in 1517, the Ottomans seized the major ports of the Maghreb: Tripoli, Tunis, Algiers, and Tangier. Ongoing conflict with Christian Europe, however, kept the Ottomans from extending their control of the Maghreb into the interior. In addition, the port cities--important bases from which to raid European shipping in the western Mediterranean Sea--remained largely autonomous from central Ottoman control In the 16th century Morocco rose as an independent kingdom, reaching the height of its power under Ahmad al-Mansur, who ruled from 1578 to 1603. In 1591 alMansur attempted to seize control of the trans-Saharan gold trade by sending an invasion force across the desert to occupy the West African empire of Songhai (see the Songhai Empire section of this article). The occupation of Songhai, however, was more of a drain on Moroccan resources than a benefit, and during the 17th century local West African rulers asserted their independence from Moroccan control. E The Age of Empires in West Africa By the 10th century North African trading powers were clamoring for gold from West Africa to satisfy the Islamic world's increasing demand for currency. This stimulated the growth in sub-Saharan West Africa of large trading empires, which accrued vast amounts of wealth and power by controlling trans-Saharan caravan routes. E1 Kingdom of Ghana The Kingdom of Ghana arose among the Soninke-speaking farmers of the transition area between desert and woodland in what is now southeastern Mauritania. Ghana exploited its strategic position between the gold-producing peoples of the south and the camel caravans of desert nomad traders to the north. From their capital at Kumbi Saleh (Koumbi Saleh) Ghana's rulers were able to tax the gold trade and build an empire which by 1000 stretched from the Sénégal River valley in the west to the great bend of the Niger River in the east. The rulers of Ghana converted to Islam following the rise of the Almoravid empire in the 11th century, easing communication along the growing network of trade routes across the desert. However, these improved trade conditions also provided the opportunity for the growth of rivals to Ghana's control of the gold trade. Increased competition combined with overexploitation of the environment at Kumbi Saleh led to the decline and eventual breakup of the Kingdom of Ghana in the early 13th century. E2 Mali Empire Soninke and Mandinka (also known as Mandingo or Malinke) clans were among the first to break away from Ghana. In the 1230s Mandinka leader Sundiata Keita organized a coalition of clans in the fertile valley of the upper Niger River, and began bringing neighboring groups under his control. This growing state became known as the Mali Empire. Under Sundiata's successors, known as mansas, the empire would grow far larger than Ghana had ever been. At its height in the 13th century, Mali stretched from the Atlantic Ocean coast in the west to beyond the Niger bend in the east, and from the goldfields of modern Guinea in the south to the major southern Saharan caravan stops in the north. Mali came to the attention of the wider world when Mansa Musa made a lavish pilgrimage to Mecca by way of Cairo from 1324 to 1325. In this period, the city of Tombouctou (Timbuktu), northwest of the Niger bend, achieved world fame as both a center of the gold trade and of Islamic learning. Holding such a massive empire together required energetic and forceful leadership. When brief reigns and dynastic struggles weakened the rule of the mansas in the late 14th century, Mali's outer provinces asserted their independence. From south of the Niger bend, powerful Mossi states raided the center of the empire, and Tuareg nomads from the desert captured Tombouctou. By 1500 the rule of the mansas of Mali stretched little beyond the Mandinka heartland of the upper Niger. E3 Songhai Empire Songhai, with its capital at Gao on the east side of the Niger bend, had been a riverside trading kingdom since at least the 8th century. Songhai was one of the first states to break away from Mali's imperial control, using an army of horsemen and a fleet of war canoes to assert independent control over the Niger bend by the end of the 14th century. Songhai became an empire in the second half of the 15th century, under the rule of military hero Sunni Ali. Expanding his territory through military conquest, Ali seized control of Tuareg Tombouctou and drove the Mossi south of the Niger bend. By Ali's death in 1492, Songhai had completely eclipsed Mali and stretched from the Atlantic coast to what is now central Niger. Ali was succeeded by Muhammad, founder of the Askia dynasty. A devout Muslim, Muhammad consolidated Ali's conquests and strengthened the administration of the empire. He used Islam as a unifying force within the empire, once justifying a major raid against the Mossi by declaring it a jihad, or holy war. Trans-Saharan trade flourished under Muhammad, who extended the empire to incorporate the Taghaza salt mines of the central Sahara. In the late 16th century Songhai suffered a series of dynastic conflicts that weakened central control. Rising states in the east--such as Bornu, the Hausa city-states, and the Tuareg sultanate of Aïr--drew trade away from the empire. At the same time, gold produced in the southern forest regions was being redirected towards the increasing presence of European traders on the West African coast. The unity of the Songhai empire ended with the Moroccan invasion of 1591. E4 Kanem-Bornu In the Lake Chad region, far to the east of the Niger bend, trans-Saharan trade was controlled by the state of Kanem, founded by Nilo-Saharan Kanuri nomads in about 800. By 1000 Kanem came under the leadership of the Saifawa clan, who established an Islamic dynasty and a settled capital at Njimi, north of Lake Chad. Kanem controlled the shortest route across the desert, by way of the highlands of Aïr (in what is now north central Niger) and the Libyan region of Fezzan. Its traders also had access, by way of the Sudanese regions of Darf?r and Kordofan, to the markets of the Sudanese Nile and ultimately to Egypt. Kanem traded copper and salt from the desert, horses from North Africa, and ivory, ostrich feathers, and slaves from the south. In the 13th century, Kanem's army was 40,000 horsemen strong, and the state controlled trade as far north as Fezzan. Near the end of the century Kanem absorbed the state of Bornu, southwest of Lake Chad, and moved its capital to Birmi, in the grasslands of Bornu. In the 16th century the rulers of Kanem-Bornu strengthened their control over the region with firearms imported from Ottoman North Africa. E5 Hausa City-States Between 1000 and 1200 seven Hausa city-states emerged as regional trading powers in the savanna lands west of Bornu in what is now northern Nigeria. These cities were centers of agriculture and manufacturing, and each developed its own specialized manufactured product, such as cotton cloth, dyes, or leather. The most important of these cities were Kano, Katsina, Zaria, and Gobir. In the south, Zaria raided the Benue River valley for captives to sell as slaves, either for internal Hausa use or for sale to Bornu and North Africa in exchange for horses and guns. E6 People of the West African Forest South of the savanna, in the forest zone from Sierra Leone to Nigeria, political organization tended to be clan- or village-based. However, several larger states emerged: The Yoruba kingdom of Ife and the Edo kingdom of Benin developed deep in the Nigerian forest in the 11th and 12th centuries. The artisans of Ife and Benin produced finely crafted terracotta sculptures and elaborate brass, bronze, and copper castings. By the 15th century Benin had expanded to control the entire length of the Nigerian coast, while Ife had been surpassed by Oyo as the dominant Yoruba state. Farther west, in the forests of what is now Ghana, Akan-speaking peoples mined gold and traded with Songhai from about 1400. By the 16th century a number of powerful Akan chiefdoms arose, exploiting new European markets for gold along the coast. In the late 17th century several of these states merged to form the Ashanti Kingdom, which soon rose to prominence as a leading exporter of both gold and slaves. By 1800 Ashanti controlled all of modern Ghana and dominated trade with the numerous rival European trading posts along the coast. E7 Rise and Impact of the Atlantic Slave Trade The collapse of Songhai in the late 16th century coincided with the emerging importance of European trading interests along the West African coast. The combination of the two stimulated considerable movement of inland peoples and the emergence of new states within the forest zone. Initially, Europeans sought West Africa's gold, but by the 17th century demand had shifted to slaves for export to European colonies across the Atlantic (see Atlantic Slave Trade). Slavery and other forms of involuntary human servitude had long been features of African economic life (Slavery in Africa). Usually these workers--outcasts, criminals, and war captives--were considered part of their captors' societies, although at a subordinate level. Slaves had been marketable commodities for centuries in the transSaharan trade, but the European Atlantic slave trade introduced a much larger scale to the trade in human beings. Initially, the supply of captives available for sale on the coast was generally the result of specific local wars connected to the rise and fall of states. For example, the forest kingdom of Benin supplied the Portuguese with captives as the kingdom expanded in the 1490s, but when the kingdom stabilized it stopped supplying captives. Similarly, wars waged by the expanding states of Fouta Djallon, Oyo, Dahomey, and Ashanti in the 17th and 18th centuries produced specific peaks of captives for sale into slavery. Basically, African rulers sold captives when it suited them, becoming rich and powerful in the process, and rarely took them from their own people. In the 18th century, as European demand grew for products such as sugar, tobacco, rice, indigo, and cotton, and as more North American, South American, and Caribbean lands became available for European use, the need for plantation labor increased. Demand for slaves exploded, growing to between 50,000 and 100,000 a year. As African war leaders and merchants fed the increasing global economic demand for slaves, they altered the nature of the trade and also changed everyday African life all along the coast and far into the interior. Systematic slave raiding became common, warfare became much more widespread, and small, village-based communities suffered badly at the hands of powerful neighbors. From the mid-15th century to the late 19th century at least 12 million young adults were sent from Africa to the New World as slaves, some 2 million of them dying en route. Combined with the millions of African slaves sent to the Mediterranean and Middle East, and the millions more who died in the process of capture, transportation, and detainment within Africa, the total number of productive young Africans lost to the slave trade exceeded 20 million. F Early East Africa Early Iron Age Bantu-speaking farmers spread their settlements widely along the Indian Ocean coast and throughout the better-watered and wooded regions of the East African interior during the early centuries AD. The drier regions largely remained the domain of cattle-herding peoples, many of them descendants of earlier Cushitic-speaking herders. F1 States of the Great Lakes As woodland was cleared for cultivation, wider areas of East Africa became suitable for cattle keeping. In the centuries before and after 1000, Nilotic-speaking cattle herders pushed southward into the newly exposed grasslands of the Great Lakes region. Some retained their Nilotic language and culture, such as the Luo northeast of Lake Victoria. West of Lake Victoria, Nilotic herders integrated into Bantu society and adopted local Bantu languages. In this period local state structures began to emerge. In the 14th and 15th centuries, the states of Bunyoro, Ankole, Karagwe, and Buganda were established in what is now Uganda and northern Tanzania. By the 16th century Bunyoro had grown to dominate the region. In the same period the hierarchical kingdoms of Rwanda and Burundi emerged in the mountains bordering Lake Kivu and Lake Tanganyika. These kingdoms were ruled by a cattle-owning aristocracy, known as Tutsi, who exacted tribute from the farming population, known as Hutu. The distinction between Tutsi and Hutu was one of power and wealth rather than ethnicity, although so-called ethnic differences between the two would be distorted and exploited in modern times. The kingdom of Buganda, located at the northwest corner of Lake Victoria, grew in stature by the early 18th century. The region's rich, fertile soil and regular rainfall supported intensive banana cultivation, which in turn supported a dense population and allowed for the development of a powerful, centralized state. Power rested with the kabaka (king) who controlled his realm by granting land estates to regional chiefs. A sophisticated system of roads and administration was established and by 1800 Buganda rivaled Bunyoro as the major power of the region. To the east, Nilotic herders moved into the Kenya highlands and the Eastern Rift of the Great Rift Valley. Absorbing southern Cushitic-speaking cereal farmers and herders, these peoples were the ancestors of the Kalenjin of Kenya and the Dadog of Kenya. Subsequent Nilotic migrations, from the 16th to the 18th centuries, created the Karamojong and Teso of northeastern Uganda, the Samburu and Turkana of northwestern Kenya, and the Masai of the central Kenyan rift valleys and northern Tanzania. The pastoral Masai traded with the Bantu-speaking Kikuyu (Gikuyu) and Kamba of the central Kenya highlands and maintained peaceful relations with them. Most of the Bantu-speaking farmers of Kenya and Tanzania lived in small, clan-based chiefdoms, but sizeable states emerged among the Chagga, Pare, and Shambaa in the wetter hills of northeastern Tanzania. In central and western Tanzania, the Nyamwezi became experienced traders in iron and salt, establishing important links between the coast and the emerging states of the western Great Lakes region. F2 Swahili and East Coast Trade About 2,000 years ago, the Indian Ocean coast was populated by Bantu-speaking farmers, cattle keepers, and fishers. These people established small village settlements on estuaries and islands and built small boats for fishing, communicating, and trading along the coast. This region was known to Greek and Roman traders of the early centuries AD as Azania. By this time Bantu settlements stretched from the Kenyan island of Lamu in the north to the Rufiji estuary near modern-day Dar es Salaam, Tanzania, in the south. These communities exported ivory, rhinoceros horn, tortoise shell, and other goods. With the ongoing spread of Islam, from the 8th century the communities of the East African coast became more directly connected to the long-distance trading network of the Indian Ocean. Muslim Arabic-speaking traders settled along the coast and married into local ruling families. The language and culture that developed remained distinctly African, but with Arabic and Islamic borrowings and influences. This language and culture, and the people in general, are referred to as Swahili. By 1000 Swahili trading settlements stretched from Mogadishu in the north to Mozambique, the Comoros archipelago, and northern Madagascar in the south. (By this time, Madagascar had been settled by Polynesian peoples from the eastern Indian Ocean.) Other major Swahili towns included Mombasa, Kilwa, Dar es Salaam, and Zanzibar. The more prosperous Swahili towns minted their own copper and silver coins. Gold from the southern African interior became a significant export in southern Swahili towns, while northern towns sold captives for slave labor. Most of these slaves were sent to the Middle East, many to work in southern Iraq collecting salt from coastal flats. The growing significance of the Swahili gold trade prompted further Arab immigration in the 12th century. Wealthy Muslim elites ruled the Swahili cities, and their imports of fine Indian and Chinese pottery hint at the range and wealth of their Indian Ocean trading connections. After Portuguese sailors first rounded southern Africa at the end of the 15th century, Portugal sought to seize control of this lucrative Indian Ocean trade, especially the gold trade. The Portuguese sacked several of the principal Swahili cities, built a string of fortresses along the coast, and dominated the coastal trade until an Arab force from Oman drove them out of the northern cities in the 1690s. G Early Central Africa In Central Africa, the Bantu migration came full circle. By 1000 BC western Bantu-speaking farmers had crossed the Congo River and settled in what is now Angola. Approximately 1,500 years later, eastern Bantu-speaking groups--descended from groups that had spread throughout East Africa--met and intermingled with their distant relatives in what is now Angola, southern Democratic Republic of the Congo, and western Zambia. G1 Luba, Lunda, and Maravi Empires In the Upemba Depression, in what is now southern Democratic Republic of the Congo, the ancestors of the Luba people made up one of the earliest iron-working groups in Central Africa. This wet, fertile savanna woodland on the southern edge of the equatorial forest was ideally suited to the production of food and the development of settled communities. In addition, the upper Lualaba River provided the Luba with trading connections between the forest and the southern savanna. They traded salt, iron, and dried fish, and became expert craftsmen in copper imported from the south. By 1300 they had organized into prosperous farming and trading chiefdoms and were casting copper into cross-shaped ingots for use as trading currency. From these origins, a great, centralized Luba Empire emerged by the early 1400s. According to traditional accounts, in the 1450s the growth of the Luba Empire inspired a sense of unity among the scattered Lunda chiefdoms to the west. New dynasties arose, but they recognized the authority of the existing Lunda rulers. The Lunda Empire that emerged in the 16th century was more like a confederation of tribute-paying chieftaincies than a single, centralized empire. Luba and Lunda ideas of kingship and inheritance of power spread farther west, to present-day Angola, and southeast, to eastern Zambia and southern Malawi. The Phiri clan, which grew powerful in southern Malawi in the early 1400s, claimed to inherit its authority from Luba kings. The Phiris married into the local Banda clan and developed their own concept of kingship, based upon the authority of local religious cults. Over the course of the 16th century they founded the Kalonga, Lundu, and Undi kingdoms--known collectively as the Maravi Confederacy--in the rich elephant-hunting lands between Lake Malawi and the Zambezi River. They profited greatly from the ivory trade with the Portuguese at the Swahili coast. For a brief period between 1600 and 1650 the Maravi were united under the Kalonga dynasty as a single empire from the Shire and Zambezi river valleys to the coast of Mozambique. In the early 18th century the king of the Lunda Empire sent a small force eastward to capture the Luapula River valley (on what is now the northern border of Zambia). The leader of the invasion was given the title Kazembe, with authority to extend Lunda tribute collection over the people of the region. In the fertile valley, which brimmed with fish and was close to the rich copper deposits in northern Zambia, this leader was able to build an autonomous Kazembe empire. By 1800 Kazembe still nominally acknowledged Lunda authority but, in practice, independently controlled a vast trading network that stretched nearly the width of the continent. G2 Kongo and Portuguese Interference Before 1000 Bantu-speaking farmers had developed numerous small states in the hills and valleys of present-day Angola and in the woodland savanna country on either side of the lower Congo River. By 1400 a number of these states had merged to form the kingdom of Kongo with its capital at Mbanza Kongo, south of the Congo River. The nearby Pool Malebo, a lake formed by a widening in the river, was a major trading junction of the lower Congo region. By controlling the pool, the kings of Kongo were able to dominate trade on the river and regional overland trade as well. Kongo was a federation of provinces and the king was elected by the hereditary rulers of the provinces. By the 1480s, when Portuguese explorers first visited Kongo, the capital housed 10,000 to 15,000 people, occupied in trading and in manufacturing iron and raffia cloth. This great concentration of people gave the king the power to challenge the local authority of the provinces. The power struggle between the king and the provinces was to be a dominant theme of Kongo's history over the next 200 years. The Portuguese emissaries and missionaries who arrived in the 1490s became one more element in the internal struggles. The Kongo king welcomed the Portuguese, seeking to gain strength from their weapons technology, and converted to Christianity. Kongolese Christianity retained distinctive African beliefs and rituals, despite the efforts of Portuguese missionaries to quash them. It became more of a royal religious cult than a religion of the masses. The king's power declined in the 18th century, but the Kongolese form of Christianity persevered, incorporating further African qualities and strengthening indigenous African religious thought. Politically, the Portuguese were arrogant and unreliable allies and refused to consider their relationship with Kongo as a meeting of equals. They intervened in dynastic struggles and entered into wars in the interior. By the mid-16th century it was clear that Portugal's primary objective was to acquire slaves for their plantations on the island of São Tomé and, later, in Brazil. The kings of Kongo were prepared to wage war against rebellious provinces in order to acquire captives for sale, but they objected to the Portuguese dealing directly with the provinces, independent of royal control. The Portuguese fueled rebellions in the provinces, culminating in a civil war that virtually destroyed the kingdom in the 1660s and 1670s. By this time the Portuguese had shifted the focus of their slave trading south to the port of Luanda, where they established the colony of Angola. Here, they continued their disruptive practices, clashing with the nearby kingdoms of Ndongo and Matamba. Queen Nzinga of Matamba was one of their foremost opponents from 1624 to 1663. From north of the Congo River, English, Dutch, and French traders tapped into the trade in Central African captives, and in doing so stimulated even higher levels of conflict in the region. The impact of the Atlantic slave trade was deeper and longer felt in this area than in any other part of the continent. By the 18th century the slave-raiding frontier stretched far into the forest to the heart of Central Africa. H Early Southern Africa By 650 small Bantu-speaking communities of ironworkers and farmers had settled all over southern Africa, excluding only the drier regions of central and western Botswana, Namibia, and the Cape of Good Hope region of South Africa. In these drier areas, Khoisan hunter-gatherers and herders were dominant. H1 State Formation in Southern Africa Some southern Bantu groups may have learned how to herd cattle by absorbing Khoisan herders into their societies. From the 7th century on, cattle keeping came to be associated with the rise of chiefs. Owners of large herds were able to lend cattle to poorer people for milk and, upon the consent of the lender, for consumption or sale. In this way, cattle-owning chiefs acquired subjects, dependent upon their wealth and continued goodwill. Chiefdoms first developed into fairly large states in the cattle-raising regions of eastern Botswana. Archaeological evidence has shown that on several flat-topped hills in eastern Botswana there were large settlements of wealthy people surrounding enclosures that would have held several hundred cattle. In the areas surrounding each of these hills were numerous smaller hilltop settlements, not as rich in their possessions or in numbers of cattle. Scholars hypothesize that each of the larger hills was the capital of a kingdom, and the smaller hills represented subordinate chiefdoms. In the flat land between the hills lived the peasantry, probably Khoisan, who tended the cattle, hunted, and tilled the fields for their patrons. These states are collectively known as the Toutswe culture, named after Toutswemogala, one of the hills. The Toutswe people established indirect trading links with the Indian Ocean coast by way of the Limpopo River valley. The Toutswe hills were abandoned and the people dispersed in about 1300, for reasons that are not yet known. Other similar state systems were established in the Lake Ngami region of northwest Botswana. A similar cattle-keeping culture developed on the western Zimbabwe plateau, near the modern city of Bulawayo, from about the 10th century. Here farmers terraced hillsides to retain moist soils for cultivation, and miners worked the region's rich gold seams. This western Zimbabwean culture reached its height between 1100 and 1300 when it developed close links with Mapungubwe, in the Limpopo valley in what is now northern South Africa. Mapungubwe was a wealthy, cattle-keeping state that traded gold and ivory with the coast. After about 1250, however, the focus of trade, wealth, and political power shifted to the kingdom of Great Zimbabwe on the eastern edge of the plateau. H2 Great Zimbabwe Great Zimbabwe started as a hilltop settlement in the early 13th century. Possibly chosen for some religious significance, the location also had a number of distinct political and economic advantages. The land was fertile and well watered, and the site was strategically situated at the head of the Sabi River valley, midway between the goldfields of the western plateau and the Indian Ocean coast. With cattle forming the basis of the state's power, its location on the edge of the plateau provided a range of upland and lowland grazing. There was a plentiful supply of timber for firewood, building, and the production of charcoal for smelting, and hunters collected ivory from the area's abundant elephants. The volume of gold trading in Great Zimbabwe grew so large that Swahili traders built a new Indian Ocean port at Sofala, due east of Great Zimbabwe, to facilitate the trade. In exchange for gold, the Swahili traded pottery from East Asia and other luxuries to Great Zimbabwe. At its height in the 14th century, the capital city of Great Zimbabwe housed up to 11,000 residents. The great stone walls for which Great Zimbabwe is famous were built with slabs of locally available granite carved so carefully that no mortar was required to hold them together. The Great Enclosure, built in the valley between 1300 and 1400, was constructed to enhance the prestige of the king rather than for defensive purposes. Great Zimbabwe was abandoned in about 1450, possibly due to the kingdom's overexploitation of the environment, but its stone ruins remain to this day as a monument to this large and thriving early Shona state. H3 Mutapa and Other Zimbabwean States Great Zimbabwe was quickly followed by the rise of Mutapa, a Shona empire at the headwaters of the Mazoe River to the north. Mutapa was likely founded by migrants from Great Zimbabwe itself. In the 15th and 16th centuries it dominated the gold trade between the plateau and the Zambezi River valley, notably with Swahili trading posts at Sena and Tete. In the 16th century the Portuguese established bases at both posts in an attempt to seize control of the trade and conquer Mutapa and the plateau. Mutapa resisted Portuguese intrusion until the mid-17th century, when the empire was at last subjugated. On the western side of the Zimbabwean plateau, Torwa (also called Butua) was founded in the 15th century as another successor state to Great Zimbabwe. At Torwa's capital city of Khami, masons continued to refine Great Zimbabwe's tradition of building precise stone walls. In the 1670s a new power arose on the plateau led by a Shona military ruler called the Changamire. His army of followers, known as the Rozwi, seized control of Torwa, drove the Portuguese from the plateau in 1693, and established the Rozwi Empire (also called Changamire). H4 Dutch at the Cape In the mid-17th century a new force appeared at the southwestern tip of the continent. The Dutch East India Company established a trading station at the Cape of Good Hope to provision their ships heading to Dutch colonies in Indonesia. Subsequent Dutch and other European settlers used firearms to seize control of the region, subjugate the Khoisan, and strip them of their cattle. These white settlers established wheat farms and vineyards in the Cape region, worked by imported slaves or Khoisan forced labor. Other settlers moved into the interior, establishing large cattle ranges and hunting lodges before moving on when resources were exhausted. By the 1770s their settlements had reached as far east as the lands of the southernmost Bantu farmers. Here they met well-established and powerful Xhosa kingdoms that could command armies sufficient to halt the settlers' advance. Thus began a century of conflict between the Xhosa and the Cape invaders. I North Africa to the 1870s By the final decade of the 18th century Africans had survived several centuries of outside interference and remained largely in control of their own destinies. Ottoman control over North Africa had declined in the face of increasing European dominance of Mediterranean Sea trade. For the most part, Egypt and the coastal settlements and ports of the Maghreb acted independently of central Ottoman authority. To the west, Morocco remained an independent kingdom, but the king's power did not extend far beyond Morocco's major cities. In the desert regions to the south, trans-Saharan caravans continued to ply their trade between the southern savanna lands, the salt mines and oases of the desert, and the Mediterranean world. However, the scale of trans-Saharan trade had declined considerably from its height in the 16th century. This was largely due to the rising importance of European seaborne trade along the West African coast. I1 Egypt and Sudan French general Napoleon Bonaparte invaded and conquered Ottoman Egypt in 1798. The Ottomans retook Egypt in 1801, but the French invasion sparked important changes in the province. A key figure in the Ottoman reconquest was Muhammad Ali, leader of an Albanian regiment of the Ottoman army. The French invasion had weakened the old Egyptian Mamluk aristocracy and Muhammad Ali seized the opportunity to establish himself as the ruler of Egypt. The position was recognized by Ottoman sultan Selim III, who awarded Ali the title pasha (viceroy) in 1805. Determined to establish his own dynasty in Egypt, Muhammad Ali built a professional army to withstand any future foreign invasions. Soldiers were conscripted from the peasantry and from slaves brought north from Sudan. Muhammad Ali ordered the massacre of most of the leading Mamluks and took over their tax-collecting powers. Then he set up a professional civil service, whose principal role was to reap as much tax income from peasant farmers as possible. To this end, his new civil servants directed the rebuilding of irrigation canals and introduced modern agricultural methods to the peasantry. Egypt's peasant farmers produced cotton and wheat in huge quantities, and the state took a large portion of the harvest in the form of taxes and exported it to Europe. In the 1820s Muhammad Ali sent an army to invade and occupy the upper Nile. The army conquered the Funj sultanate and established the administrative capital of Khartoum at the junction of the Blue Nile and the White Nile. By the 1840s Ali had extended Egypt's empire to include most of what is now southern Sudan. Rich in ivory and slaves, this area was a good source of wealth and of forced recruits for the Egyptian army. The Arab Egyptian merchants who set up their headquarters in Khartoum, using what were in effect private armies, chose to raid southern Sudanese settlements of Dinka, Shilluk, and Nuer peoples for goods rather than trade for them. In doing so they established a pattern and frame of mind for the relationship between Sudan's Arabs and black Africans that was to persist all the way into the 21st century. Muhammad Ali's grandson Ismail Pasha, who ruled from 1863 to 1879, allowed European traders to settle in Egypt. Ismail encouraged Europeans to invest in the construction of railways and also in the digging of a canal to link the Mediterranean Sea to the Red Sea at Suez. France financed the construction of the Suez Canal, which opened in 1869. Egyptian cotton production for the British market increased rapidly during the American Civil War (1861-1865), when cotton supplies from the United States were cut off. Overconfident of Egypt's economic position, Ismail began undertaking costly endeavors such as building a railway to Khartoum and investing heavily in garrisons in southern Sudan to suppress Sudanese resistance. By the mid-1870s it was clear that Ismail's government had overstretched itself and was bankrupt. Britain and France--fearful that the Egyptian state might collapse and they would lose their huge investments in railways and canal--intervened, deposing Ismail in 1879. The two European powers established a system of "dual control" over Egypt's finances. When an Egyptian army coup threatened to drive out the Europeans, Britain sent an army of occupation and took over sole control of Egypt in 1882. I2 Algeria and the Maghreb The rulers of Algeria supported the French in their 1798 invasion of Egypt and supplied Napoleon's army with wheat, on credit, throughout the subsequent Napoleonic Wars (1799-1815). Thereafter, however, the French refused to repay their debt to Algeria and relations between them soured. In 1830 the French army occupied Algiers and overthrew the Algerian ruler. France annexed Algiers and the fertile coastal region in 1834 and invited in French settlers to occupy the land. Beyond the coastal regions, however, the French met the formidable resistance of Arab and Berber Muslims, led by marabout (Muslim holy man) Abd al-Qadir. By the 1840s the French needed an army in excess of 100,000 men to maintain their occupation and to wage the ongoing war. Although Abd al-Qadir was captured in 1847, French conquest of Algeria was not completed until the 1870s. In the early 19th century the rulers of Libya and Tunisia, acting independently of Ottoman control, bought firearms from Britain and used them to extend their control into the interior regions of the Sahara. Libya took control of the Fezzan region in 1811 and thereafter stepped up the trade in slaves from the Bornu region by Lake Chad. The kingdom of Morocco maintained its independence throughout the 19th century, despite clashes with Spain along the Spanish-controlled northern coast and with France on the Algerian border. At the same time the Moroccan sultans extended more effective control over the remoter Berber regions of the interior. J West Africa to the 1870s From the 17th to the 19th century in sub-Saharan West Africa--from the Sénégal River estuary in the west to Cameroon in the east and as far south as Angola--political and economic life was dominated by the demands of the European-controlled Atlantic slave trade. By the late 18th century the scale of this trade had reached unprecedented heights, with up to 100,000 captives exported every year. The wars that generated this traffic in captives dominated life in the interior. States with standing armies became more centralized and more powerful, dominating smaller, village-based communities. For the most part, European presence was confined to coastal fortresses, which were fortified against European rivals rather than local Africans. Coastal African rulers tolerated the European presence because the European fortresses provided useful trading links that strengthened their positions against their own African rivals. Two important developments occurred in 18th-century West Africa that presaged large-scale change in the 19th century. First, by the mid-18th century a rise in Islamic reformist zeal led to several jihads and the establishment of new Islamic states in Fouta Djallon (in what is now Guinea) and Fouta Toro (in Senegal). Second, in the 1780s and 1790s Britain helped freed slaves from Britain and North America establish settlements in the British territory of Sierra Leone. The Islamic states of Fouta Djallon and Fouta Toro served as inspirations for larger 19th-century West African jihads, while the colony of Sierra Leone was symbolic of the emerging abolitionist movement that would eventually bring an end to the Atlantic slave trade. J1 Jihads and New States in 19th-Century West Africa West African Islamic reformist ideas of the late 18th and early 19th centuries were spread by Fulani peoples, who had played a prominent role in the earlier jihads of Fouta Djallon and Futa Toro. The Fulani--largely Muslim cattle herders who lived in the savanna lands from Senegal to Cameroon--typically lived in peace among farming populations. However, in the Hausa region of what is now northern Nigeria the Fulani became estranged from what they regarded as the corrupt rule of the nominally Muslim Hausa aristocracy. They particularly resented the Hausa's heavy taxation of their cattle. The Fulani were therefore very receptive to the reformist teachings of Muslim scholar Usuman dan Fodio, who had begun his preaching as a young man in the 1770s in the Hausa city-state of Gobir. By the early 1800s Usuman had accumulated a considerable following. In 1804 the ruler of Gobir sent his cavalry to capture or kill Usuman, but the force was defeated by his followers. This military action sparked a spontaneous revolutionary movement among Fulani and other oppressed Muslims across the whole of Hausaland. Within four years most of the Hausa city-states had fallen to the jihad. After Usuman's death in 1817 his brother Abdullahi and son Muhammad Bello united the Hausa states into a single Islamic empire, with its capital at Sokoto. This brought an end to centuries of rivalry and clashes between the states. By the time of Muhammad Bello's death in 1837 this Sokoto Caliphate stretched across the whole of northern Nigeria and was the largest West African state since 16th-century Songhai. Islam and Sharia (Islamic law) made up the unifying elements in what was otherwise a federation of semiautonomous emirates. Literacy became widespread and, with an end to interstate Hausa wars, trade flourished. Those who benefited least were the Hausa peasantry, who had in effect changed one oppressive master for another. Fulani pastoralists tried to extend the jihad into Bornu, but they were resisted by Muhammad al-Kanemi, a religious and military leader from Kanem. Although the state lost control of its eastern Hausa provinces, Bornu retained its independence under a new dynasty set up by al-Kanemi's son Umar. West of Sokoto, Usuman dan Fodio's revolution inspired further Fulani-led jihads and political change. On the upper Niger River, a jihad was led by Umar Tal, a Muslim preacher from Fouta Toro. In the Fouta Djallon region, he built up an army and equipped it with firearms, bought in exchange for captives on the coast. From 1855 to 1862 Umar's army captured the Bambara states of Kaarta and Ségou, and the Fulani state of Macina. He thus created what was known as the Tukolor Empire, which stretched from Fouta Djallon to Tombouctou. Following Umar's death in 1864, Tukolor was weakened by internal revolts and was conquered by the French in 1893. South of Tukolor, in what is now Guinea, military leader Samory Touré conquered and united the states of the Dyula people in the 1860s, creating the powerful Mandinka state. Unlike some of his contemporary state-builders, Samory was not a religious preacher and Mandinka was not a reformist state as such. Nevertheless, he used Islam to unite the nation, promoting Muslim education and basing his rule upon the Sharia. Samory's professional army was the real strength of what had become a Mandinka empire by the 1880s. As such it provided one of the major forces of resistance to French conquest in the final decades of the century. J2 Abolition of the Slave Trade How the Atlantic slave trade came to be abolished has been the subject of ongoing historical debate. The traditional view argued by British historians for much of the 20th century was that the abolition of the slave trade was the result of a humanitarian campaign spearheaded by a handful of prominent British philanthropists. This view was challenged in the mid-20th century by historians who argued that it was hard economics, not humanitarian concerns, that ended the slave trade. According to this view, by 1800 colonial plantations were declining in profitability, while the spread of industry in Britain (see Industrial Revolution) was becoming increasingly profitable, making the slave trade unnecessary. Many historians now agree that the complete story of abolition was in fact very much more complex than either of these positions. Both economics and philanthropy were involved, though which was the more powerful force remains a subject of debate. Another factor, often overlooked, was African opposition to slavery, both in the form of slave rebellions in the Caribbean and resistance within Africa itself. By 1817 the major European powers had officially banned the slave trade, but it still continued, and even increased at times, until slavery itself was completely abolished (in 1865 in the United States and in the 1880s in Cuba and Brazil). While there were still markets for slaves the trade continued, despite patrols by a British naval antislavery squadron. The British captured a number of slaving ships and freed their captives in Sierra Leone, which had been annexed as a British colony. Later in the century Britain and other European powers would use the anti-slave-trade campaign as a justification for seizing further African territory, and eventually for their colonization of the continent. J3 Coastal and Forest Regions Africans powers had not been consulted in the official European ban on slave trading, and states in many areas, eager to acquire European firearms, continued to supply the European, American, and Brazilian ships that evaded the ban. One such area was the Yoruba lands of present-day southern Nigeria, which had not previously been a great supplier of captives for sale into slavery. But when the Fulani jihad spread southward from Sokoto in the 1820s it destabilized the Yoruba state of Oyo and prompted warfare across the whole of Yorubaland. Increasing numbers of Yoruba war captives were subsequently transported to the Lagos lagoon for export as slaves. This provided the British with the excuse to seize control of Lagos in 1851 in the name of suppressing the slave trade. In reality it provided the British with a colonial foothold. They declared Lagos a colony in 1861 and, over the next 40 years, gradually extended British control over the whole of what was to become the colony of Nigeria. The Kingdom of Dahomey, in what is now southern Benin, used the Yoruba wars as an opportunity to break free of Oyo domination and assert its independence. With the backing of a large standing army, Dahomey's kings built a highly efficient and powerful centralized state. Dahomey's wealth was originally derived from the slave trade, but as the trade was suppressed in the mid-19th century, the king turned to the exploitation of the region's numerous oil palm plantations. Palm production that was not directly controlled by the state was taxed in a highly efficient manner. When the French took over the territory at the end of the century, they estimated that it contained 40 million palm trees. The Ashanti Kingdom, in what is now Ghana, was the largest and most powerful West African forest state throughout most of the 19th century. Ashanti derived its wealth from the production of gold dust, which it traded with British, Danish, and Dutch traders on the coast. Consequently, the region was known to Europeans as the Gold Coast. The British sought to control the gold trade, and allied themselves with the coastal Fante people, bitter rivals of the Ashanti, to keep Ashanti from monopolizing the trade. Ashanti and British forces clashed in the mid-1820s, but signed a peace treaty in 1826. In the 1840s the British bought a string of Danish forts along the coast and in 1872 purchased the Dutch fort of Elmina. This left Britain the sole European power in the area. The king of Ashanti challenged the rising colonial power by invading the British-held coast in 1873, sparking the Second Ashanti-British War. A British counterinvasion in 1874 penetrated deep into the Ashanti heartland where British forces sacked the Ashanti capital of Kumasi. The British withdrew, but Ashanti had been fatally weakened and finally fell to British forces in 1896. To the west, at the mouth of the Sénégal River, the French held the trading towns of Saint-Louis, Gorée, Dakar, and Rufisque. These were important bases for access to trade in gum arabic (used in dying cloth) and groundnuts from the interior. The inland Wolof state of Fouta Toro imposed taxes on most of this trade, however, and in response the French sent an army up the Sénégal River valley in the 1850s. By 1858 the army had defeated the Wolof and established a protectorate over the region. In the process the French clashed with the jihad army of Umar Tal, which prompted him to turn east, toward the upper Niger River, where he founded the Tukolor Empire. Over the course of the 19th century Sierra Leone grew rapidly, as the British transported freed African captives from all over West Africa to the colony. These mixed groups of Africans communicated in Creole (or Krio), a mixture of English and African languages, and they were known collectively as Creoles. Starting in the 1820s groups of freed African Americans began settling to the east of Sierra Leone in a region they named Liberia. These Americo-Liberians established Liberia as an independent nation in 1847. K East Africa to the 1870s By the 19th century foreign powers dominated the East African coast, but in the inland regions indigenous Africans still largely controlled their own fates. The southern Arabian sultanate of Oman extended its influence to the northern Swahili coast in the 17th century, expelling the Portuguese from the Kenyan coast by 1700 and from the island of Zanzibar in 1729. To the south, along the Mozambique coast, the Portuguese remained the dominant trading power. This region supplied captives to meet the rising French demand for slave labor on sugar plantations on Mauritius and other French-held Indian Ocean islands. In the interior, west of Lake Victoria, the lakeside kingdom of Buganda had grown to surpass Bunyoro, its older rival, in regional strength. To their south, Rwanda and Burundi had become powerful mountain kingdoms. The Nyamwezi people of the interior of present-day Tanzania were professional traders, carrying ivory between the lake kingdoms and the coast. Meanwhile, in the north, the Christian empire of Ethiopia continued to be a regional power in the highlands, while the Ottoman Empire controlled the coastal region of Eritrea. K1 19th-Century Swahili Coast As the slave trade waned in West Africa in the 19th century, it was peaking on the East African coast. By this time Brazil had become one of the main markets for the trans-Atlantic trade. Restrictions on the slave trade drove up prices in West Africa, and starting in the 1820s it became more economical for Brazilian slavers to venture around southern Africa to Mozambique. There they found a well-established slave trading system supplying local Portuguese needs as well as those of French sugar planters on various Indian Ocean islands. Afro-Portuguese settlers, known as prazeros, in the Zambezi River valley used private slave armies to hunt and raid for ivory and slaves to sell on the coast. North of the Zambezi, the Yao people played a similar role as professional raiders and traders between southern Malawi and northern Mozambique. Meanwhile, under the rule of Sayyid Sa'?d ibn Sultan, the sultanate of Oman was rising in power along the northern half of the Swahili coast. Starting in the 1820s the sultan encouraged Omani Arabs to set up clove plantations on the large offshore islands of Zanzibar and Pemba. Worked by slave labor from the mainland, these plantations became so successful that in 1840 Sayyid Sa'?d moved his primary residence to Zanzibar itself. The growth of Omani plantations prompted a huge increase in the demand for slave labor. By the 1850s Zanzibar's slave market had become the largest of its kind in Africa. Apart from local needs on the clove plantations, by the 1860s Zanzibar was exporting 60,000 slaves a year, mostly to Arabia and the Persian Gulf. The increasing demand for slaves stimulated expeditions by Swahili-Arab and Nyamwezi slaving caravans into the African interior, to the Great Lakes region and beyond. Following the 1873 death of Scottish missionary-explorer David Livingstone, who had done much to bring the horrors of the African slave trade to the attention of Europeans, the British forced the closure of Zanzibar's slave market. By then, however, Britain's demand for East African ivory had reached such heights that slave labor continued to be used to transport it to the market in Zanzibar. In the last decades of the 19th century, Britain was to make the suppression of the inland slave trade its moral justification for the colonization of much of the region. K2 Political Developments in Ethiopia Ethiopia had been independent and regionally powerful for 1,000 years before facing a political crisis in the 19th century. Before the 17th century Ethiopia had a roving capital which moved from province to province, helping the Ethiopian emperor retain effective central authority. However, in the 17th century Gondar (Gonder) gradually became the fixed capital, allowing Ethiopia's regional nobility to develop a stubborn autonomy in their isolated valleys. Ethiopia became an increasingly fragmented feudal state until the mid-19th century, when Ethiopia's relative security was threatened by the expansion of Egyptian control over southern Sudan. In response, a provincial leader named Kassa Haylu developed a trained army equipped with modern firearms and artillery. In 1855 he seized the Ethiopian throne and declared himself Emperor Theodore II. Theodore saw that if he did not modernize Ethiopia's military and unify the empire, it was in danger of being overrun by more powerful external enemies. He expanded his own fighting force, and built it into a modern national army. He stripped the hereditary provincial nobility of powers and appointed paid governors and judges to take their places. Fearing the power of the Ethiopian Church, Theodore seized much of its land and limited the number of clergy. These efforts to forge national unity made Ethiopia more powerful but earned Theodore many enemies. In 1868, following a minor diplomatic row, Theodore arrested some British consular officials. In response, Britain invaded with an army of 30,000 men. The Ethiopian Church helped convince the majority of Ethiopian nobility to abandon their emperor in his hour of need. Left with only 4,000 men, Theodore's army was easily overrun and he himself committed suicide. The British withdrew, leaving Europeans with the erroneous notion that Ethiopia could easily be captured in the future if the need arose. Theodore's successor, Johannes IV, regained the support of the Ethiopian Church and regional nobility by restoring their hereditary powers and privileges. In doing so he was able to summon a large enough army to defeat an Egyptian invasion in 1875, but at the expense of entrenching the feudal system into the fabric of Ethiopian economy and society. L Central Africa to the 1870s For centuries, the trade in captives had dominated the commercial activity of Central Africa. North of the densely forested Congo River Basin the Bornu sultanate declined by the 18th century, and its place was taken by the sultanates of Wadai and Darf?r to the east. These states conducted slave raids through what is now southern Chad and the Central African Republic and transported captives eastward through Kordofan to southern Sudan and the Nile River Valley. South of the Congo River Basin the Kazembe Empire had grown to eclipse the former Luba and Lunda empires of the region and was a powerful trading state. Meanwhile, the histories of the forest peoples of the Congo River Basin are some of the least known in Africa beyond their riverine trade contacts with peoples and states to the north, south, and west. However, these peoples became more and more threatened as Swahili slave raiders penetrated ever farther into the forest. L1 Natural Resources and Trade Besides captives, 19th-century European and Swahili traders also sought to tap into Central Africa's vast supplies of raw materials, notably ivory. In response to the demand for ivory, some Central African peoples became professional elephant hunters. The Chokwe hunted elephants across the southern fringes of the forest, supplying ivory to Portuguese traders in Angola. Similarly, north of the Congo River, the Fang expanded from southern Cameroon into the forest of Gabon to supply ivory to European traders at the coast. Other raw materials exported to the western coast included copper, palm kernels (the source of palm oil), cotton, coffee, and raw latex rubber. Africans collected these raw materials and traded them to Europeans in exchange for firearms, cloth, and other manufactured imports. Faced with competition from plentiful European manufactured goods, indigenous African industry--such as the manufacturing of iron tools, raffia cloth, and bark cloth--went into terminal decline in the 19th century. This economic pattern--Africa's dependent role as an exporter of raw materials and an importer of manufactured goods--persists in much of Africa to this day. L2 Trading States of the Congo River Basin In the Luapula River valley, on the southeastern fringes of the Congo River Basin, the Kazembe Empire entered the 19th century as the driving force behind a transcontinental trading network. A Lunda state, Kazembe controlled the trade in copper, which was mined in the Copperbelt region of what is now Zambia and southern Democratic Republic of the Congo, and cast into ingots for use as currency. Besides copper, Kazembe also exported ivory, salt, and captives. The latter were sent mostly eastwards to meet the rising demand for slaves on the East African coast. By mid-19th century the demand for ivory and slaves on the East African coast was so great that coastal Swahili, Nyamwezi, and Arab or mixed-race traders began exploring west of Lake Tanganyika, penetrating the Central African interior. Leading their own trading caravans of hunters, raiders, and porters, and heavily armed with guns, they sought out new sources of ivory and slaves. In the 1850s a Nyamwezi trader named Msiri set up his own raiding and trading state west of the Luapula River in defiance of Kazembe (which at the time was suffering a civil war). This state, known as Yeke, took control of the Copperbelt and with it the western Lunda trading network. In the 1860s Hamed bin Muhammed (also known as Tippu Tip), a man of mixed coastal and Nyamwezi ancestry, established similar raiding and trading bases on the Lualaba River (the upper Congo River), west of Lake Tanganyika. Tippu Tip considered his "kingdom" an outpost of the sultanate of Zanzibar, by then Africa's largest market for ivory and slaves. The activities of traders such as Tippu Tip and Msiri brought the full horrors of the slave trade to the remotest forest regions of the Congo River Basin, which had previously been little affected by the trade. L3 Lozi Kingdom By the 19th century the Lozi Kingdom grew to dominate the savanna woodland region of the upper Zambezi River valley in what is now western Zambia. Lozi was a complex, centralized state. Its king delegated regional authority to aristocratic bureaucrats, who directed the seasonal cultivation of the Zambezi floodplains. In 1840 Lozi was overrun by Kololo raiders from what is now South Africa, but in the 1860s the Lozi dynasty and aristocracy were restored. In the second half of the 19th century, ivory hunting and cattle raiding accompanied an expanding Lozi state. M Southern Africa to the 1870s In the 18th century Sotho and Tswana states emerged on the grasslands south of the Limpopo River. As was the case with the earlier Toutswe states of eastern Botswana, cattle were an important source of power and wealth, and conflict between peoples over cattle ownership was a regular feature of 18th-century life. Across much of southern Africa population was still relatively sparse. In this setting, political change was fluid and ongoing: Dynastic clashes and disputes over cattle often led to the breakup of states and the establishment of new ones. In the Cape of Good Hope region, the spread of Dutch-speaking settlers known as Boers (ancestors of South Africa's modern Afrikaners) had largely been halted in the east by effective resistance from Xhosa herders and farmers who were themselves eager to expand their chiefdoms westward. The strategic position of the Cape to world sea trade, however, was to draw it into inter-European conflicts. The British seized the Cape from the Dutch permanently in 1806 (after having first occupied it from 1795 to 1803), adding a new dimension to European influence in South Africa. M1 The Mfecane From the 1810s to the 1830s southern Africa went through a period of violent turmoil and political upheaval in which many different chiefdoms and other states came into conflict with each other, spurring wars and large-scale migrations. This period, referred to as the mfecane (from a Nguni word meaning "the crushing"), has long been the subject of debate among historians. For years, historians generally believed that the violence was singularly the result of the emergence of an expanding Zulu kingdom under military leader Shaka. However, many historians now contend that this emphasis on Zulu expansion obscures the fact that, as we have seen, the rise and fall of similar states and conflict over the control of cattle were already very common in the region. It also ignores two important factors: Firstly, the rise in the demand for slaves along the southern Mozambique coast from the 1820s likely played a role in the emergence of some of these new states, particularly the Gaza Empire. Secondly, assaults by armed and mounted raiders from the Cape Colony region--searching for cattle and captives for sale in the colony--were also a major source of disruption among the peoples of the area. Apart from the Zulu kingdom under Shaka and the Gaza Empire under Soshangane, other new states in the region included the Sotho kingdom under Moshoeshoe, the Swazi kingdom under Sobhuza, and numerous Tswana kingdoms of the western grasslands. The Ndebele, led by Mzilikazi, left the Zulu region in the early 1820s and settled briefly north of the Vaal River, absorbing local Sotho and Tswana into their ranks. Constantly harassed by Boer, Griqua, and Kora raiders, the Ndebele moved north and established a new kingdom in southern Zimbabwe in about 1840. By this time, groups of other migrants, who came to be known as the Ngoni, had already moved north through Zimbabwe to settle in the region of eastern Zambia, Malawi, and southern Tanzania. In the far south of the region the Xhosa held out against the increasingly violent challenge of the British-occupied Cape Colony, only finally going down to defeat and colonization in the 1870s. M2 Boer Trek and Boer Republics In the late 1830s several thousand Boer families began migrating from British-ruled Cape Colony to the northeast, across the Orange and Vaal rivers. These migrants sought new expanses of land unclaimed by Europeans, as well as unrestricted access to African forced labor. Their further occupation of land in the colony had been limited by Xhosa resistance from the east, while their use of forced African labor had been restricted by the British abolition of slavery in the 1830s. These Boer trekkers established settlements in the lands north of the Orange River, farther north in the Transvaal, and in the eastern lowlands of Natal. Later in the century Boers and other Dutch-speaking South Africans began calling themselves Afrikaners. As part of a cultural and political struggle against British domination, Afrikaner historians portrayed this Boer migration as a Biblical-style "Great Trek" into unoccupied wilderness. But the reality was very different. The early Boer intrusion was challenged throughout, and many Africans died at their hands. They fought bloody battles with Zulu in the east and with Sotho, Tswana, and Ndebele in the north. The British intervened as well, annexing the colony of Natal in 1843, and seizing the land between the Orange and Vaal rivers in 1848. Eventually, however, the British recognized two independent Boer republics: the South African Republic (in Transvaal) in 1852, and the Orange Free State in 1854. M3 Discovery of Mineral Wealth By 1867 large parts of what is now South Africa were still under independent African control. However, the discovery that year of diamonds near the confluence of the Orange and Vaal rivers, followed by the 1886 discovery of the world's largest gold deposits in the Transvaal would ultimately transform the economic and political life of all southern Africans. As a vast and hugely lucrative industrial market opened up in the interior, conflict over land and labor heightened. Britain in particular was determined to bring the whole area under its imperial control. N The Scramble for Africa In the final two decades of the 19th century European colonial powers took over virtually the whole continent of Africa, racing each other to claim territory to expand their colonial empires. This so-called Scramble for Africa marked an irreparable turning point in the history of the continent. Almost overnight, most Africans lost control of their own historical destinies. Nations and whole empires were swept aside as the political layout of the continent was reconfigured according to European dictate. N1 European Motivations Historians have debated the questions of what sparked the Scramble, what Europe's motives were, and why the takeover happened so rapidly and completely. In the early 20th century the colonizing powers set the terms of the debate, arguing that they came to Africa with a "civilizing" mission. Because it morally justified their actions, they unfairly portrayed Africa as a dark and primitive continent with no discernible record of historical achievement. European powers claimed they had come to suppress the slave trade, end endemic warfare, and establish their own right to trade freely in the continent without local interference. Attempts by African rulers to control and tax the trade within their own states were arrogantly dismissed by European traders, who accused them of interfering with the free flow of trade. Income from the taxation of trade had always been an essential source of government revenue in most African states and the removal of this rightful income deliberately and seriously weakened them in the face of the European challenge. From the beginning, Europe's presumed "moral justification" for imperialism was challenged by contemporary thinkers (including British social reformer John Hobson and, later, Russian Marxist revolutionary Vladimir Lenin) who identified economics as the prime motivator underlying the European conquest of Africa. Industrial Europe needed Africa's raw materials: palm oil, cotton, rubber, and minerals. Furthermore, while the ancient gold riches of West Africa and Zimbabwe had long been known, the 1870s and 1880s demonstrated the presence of spectacular diamond and gold wealth in southern Africa. But Africa was not only a source of raw materials for European factories, it was also a vast, untapped market for the overproduction of those same factories. African indigenous industry was unable to compete with European mass-produced cloth, metal tools, and liquor. N2 Conquest of a Continent In 1877 Anglo-American explorer Henry Morton Stanley emerged at the mouth of the Congo River, completing an arduous, three-year transcontinental trek and proving the Congo's navigability for thousands of kilometers above the rapids near its mouth. Ambitious Europeans, led by King Leopold II of Belgium, recognized the river as a major potential trading artery. By the early 1880s Belgium and France had competing claims to territories on either side of the lower Congo. Territorial acquisition quickly became competitive and strategic, as Europe's major powers decided that their future economic prosperity depended on their seizing as much of the continent for themselves as possible. The biggest players were Britain, France, Belgium, and Germany, with Spain and Italy playing lesser roles, and Portugal maintaining its claims to its longstanding colonies. The process was already well under way by the time the European powers met at the Berlin West Africa Conference of 1884-1885 to lay down the ground rules of the Scramble. The principal of these was that European claimants to any part of Africa had to prove their presence in the area by getting the signed agreement of a local African ruler or--if that was not possible or convenient--by military conquest. Europeans frequently tricked illiterate African rulers into signing documents under false pretences. For example, in 1888 Ndebele king Lobengula inadvertently gave British businessman Cecil Rhodes and his private mining company the right to take over the whole of what is now Zimbabwe. The British government ignored Lobengula's subsequent protests and approved Rhodes's colonization of the country. Some African rulers, more experienced in European ways, willingly agreed to "protection" before the arrival of European military forces, and in this way managed to obtain some concessions. Lozi king Lewanika achieved better treatment for Lozi than the rest of what is now Zambia by agreeing to an 1889 British treaty of protection which left him with some power and kept the British from seizing Lozi land. European armies eventually occupied most of the continent, brutally conquering most African states that resisted. African powers lost virtually every conflict for two main reasons: the age-old principle of divide-and-conquer and the superior weaponry of the European armies. Europeans were able to play one African ruler against another because a ruler's first duty to his people was to protect them from their traditional rivals or enemies. Up to this point, Europeans had been trading partners and not necessarily rivals or enemies, roles more likely to be played by neighboring African states. Therefore, neighbors of West African slave-trading states were often prepared to help Europeans overcome their traditional enemies, who had long raided them for captives to sell into slavery. Many African states even provided military support for European colonizing armies. Despite trading firearms into Africa for more than a century, Europeans were much better armed. European armies had access to the latest weapons technology, which was developing rapidly in the final decades of the 19th century. Some African armies possessed breech-loading rifles (loaded through the rear of the barrel rather than through the muzzle), but none had the newly-developed machine gun and, with almost the sole exception of Ethiopia, none had artillery with explosive shells. African bravery and strategic skill resulted in a few memorable African victories, such as the Zulu victory over the British in the Battle of Isandlwana in 1879. However, with huge resources of equipment and soldiers at their disposal, European imperial victory was virtually inevitable. Often it was a very one-sided fight: In 1898 at Omdurman, Sudan, the British killed 20,000 Sudanese fighters in a matter of hours. Some of the longest struggles for political survival occurred in what was to become French West Africa, where Samory Touré's Mandinka state fought off French incursion from the early 1880s until 1898. Sudanese military leader Rabih al-Zubayr, using a disciplined and well-armed cavalry, waged a jihad in the Chad region and conquered Bornu in 1893. There he set up a militaristic empire that held up French conquest until 1900, when two French armies converging from north and the south finally overcame Rabih. In many parts of Africa, rural people were initially unaware of the fact that European powers had, on paper, taken over. Rural resistance to European presence, when it came, was often small in scale but long in duration. N3 Victory at ?dwa Ethiopia stands as the exception to the rule in the Scramble. Menelik II became emperor in 1889 and proceeded to use the powerful, well-equipped Ethiopian army to expand south, east, and west, incorporating the territories of the Oromo, Sidama, and Somali peoples into his empire. Italy, which had taken Eritrea from the Ottoman Empire in the late 1880s, invaded Ethiopia in 1895, anticipating an easy victory. The Ethiopian army, using breech-loading rifles and artillery, annihilated the Italian force at the Battle of ?dwa in 1896. With this victory, Ethiopia became the only indigenous African state to successfully resist European colonization during the Scramble for Africa. O Colonial Rule By World War I (1914-1918) Ethiopia and Liberia were the only independent nations left in Africa. France and Britain held the most African territory: French colonies stretched across almost all of West Africa, while Britain held an almost unbroken string of colonies from Egypt to South Africa. O1 Colonial North Africa European colonial control came earlier to North Africa than to most of the continent. As the British occupied Egypt in 1882, the French extended their control from Algeria to Tunisia. Morocco managed to resist the establishment of a French protectorate until 1912. Banding together in Islamic resistance forces, North Africans provided European colonists with their most persistent opposition. When the Italians invaded Libya in 1911 they faced formidable opposition from the Sanusi Brotherhood, who conducted a brilliant guerrilla campaign that lasted for 20 years. In the northern extent of Morocco in the early 1920s the Berbers of the Er Rif mountains almost expelled the Spanish from the region until the French came to their aid in 1926. In Algeria, Islamic brotherhoods had fought French rule for decades in the mid-19th century. However, by the 20th century French control was secure, and the French settler population rose rapidly. In early-20th-century Egypt, anticolonial opposition, protests, and riots were commonplace, as were violent British reactions. The pressure on the British, compounded by the demands of World War I, led Britain to make political concessions. In 1922 Egyptians gained nominal independence and a parliament under King Fuad I, although Britain remained in control behind the scenes. The corruption and ineffectiveness of Fuad's government undermined the parliamentary system as a viable form of government. In the 1930s an organization called the Muslim Brotherhood emerged in vehement opposition to parliamentary government as well as European culture and interference. This brotherhood inspired other movements throughout Islamic North Africa, and its impact is still felt in the region. O2 Colonial Sub-Saharan Africa Across most of sub-Saharan Africa, colonial rule was accompanied by the exploitation of the continent's raw materials by private European concessionary companies. The conduct of these companies was often brutal. The worst excesses were in the Congo (now the Democratic Republic of the Congo), which Belgian king Leopold II ruled as his personal fiefdom until it was taken over by the Belgian government in 1908. Leopold's agents used forced African labor to collect rubber, and regularly tortured and mutilated African workers. Violence by concessionary companies was also experienced in British Southern Rhodesia (now Zimbabwe); German East, West, and South-West Africa (now Tanzania, Cameroon, and Namibia); Portuguese Mozambique; and French Equatorial Africa (now several countries, including Gabon, Republic of the Congo, and Central African Republic). In the early 20th century European colonists in Africa directed the building of new infrastructures, such as port facilities and numerous railways. Railways were built with African forced labor and the railway companies were often paid with vast grants of African land or mineral concessions. Almost exclusively, the railways linked the source of a colony's agricultural or mineral wealth with ports. They were arteries by which colonizing powers extracted the continent's raw materials to benefit themselves, with virtually no thought given to local African economies. Although Europeans would later claim that they had given Africa a modern infrastructure, Africans had paid for it and Europeans were the main beneficiaries. Furthermore, land along the railways became valuable commercial farmland because of the easy access to wider urban or international markets, and so it was often set aside for white settlement. In Kenya, a railway built to link Uganda with the coast provided the British with the incentive to seize the Kikuyu highlands of Kenya for exclusive white settlement. Colonial taxation of Africans was an important method of control. Throughout much of the continent--but especially in countries with extensive white settlement, such as Kenya, Rhodesia (Zimbabwe), and South Africa--taxation was used as a deliberate tool to drive Africans into the labor market. In order to earn the money to pay the new taxes, Africans had to work European farms and mines. Colonists encouraged Africans to migrate from rural areas to work their various enterprises. They recruited men from rural areas and paid them minimal wages on short, fixed-term contracts. Colonists assumed that the workers' wives who remained behind would be able to grow enough food to feed their families' children and elderly. The reality was that rural areas became impoverished by the absence of male labor and insufficient income from wages to compensate. Women therefore often followed men to urban areas in search of casual employment, further impoverishing the rural areas. This migratory pattern would persist throughout the 20th century. African farmers who were able to retain their land grew a variety of crops for the new colonial markets. They grew groundnuts in the Sénégal and Gambia river valleys and in northern Nigeria. Palm oil continued as an important product of the forest region, from Côte d'Ivoire to the Niger River delta, while cocoa planting was adopted by the Akan of the Ashanti forest of the Gold Coast (modern Ghana). In Uganda local African initiative ensured the development of thriving cotton production for export by rail to Indian Ocean ports. Minor rebellions were widespread in colonial Africa wherever land was seized for white use, forced labor was particularly oppressive, or taxation was harshly or unreasonably imposed. Major rebellions aimed at expelling colonizers altogether erupted in Rhodesia (1896-1897), German South-West Africa (modern-day Namibia, 1904-1907) and German East Africa (now Tanzania, 1905-1907). Ultimately, however, the colonizers had the resources to summon however many reinforcements were needed to suppress these rebellions. In South Africa, Africans suffered the most extreme form of colonization. The British controlled the entire area following their victory over the independent Boer republics in the South African War, or Boer War (1899-1902). In 1910 Britain established the Union of South Africa, granting the white population--both British and Afrikaners--control of their own parliamentary government. Between 1910 and 1940 successive white governments pursued increasingly restrictive policies of segregation, which included restricting Africans to bantustans (homelands) that amounted to a mere 13 percent of the country's land area. For the most part, Africans were only allowed into the "white areas," which included all the cities, if they were employed by whites. What emerged was an unbalanced economic system based upon race, designed for the benefit of whites and dependent on the subservience of blacks. It evolved haphazardly in the first half of the 20th century, but following 1948 the National Party government codified it into the apartheid (Afrikaans for "separateness") system, which lasted until 1994. O3 Africa and the World Wars World War I impacted many parts of Africa as British, French, and Belgian forces invaded their neighboring German colonies. Africans suffered badly, mostly as noncombatant forced laborers. In addition, many thousands served in the French Army as combatants in the trenches of Western Europe. After the war, Germany's African colonies were handed over to neighboring colonial powers. World War II (1939-1945) combat was limited to Ethiopia and North Africa. Fascist Italy invaded Ethiopia in 1935 and, with the use of aerial bombardment and poison gas, conquered it in 1936. Driven into exile, Ethiopian emperor Haile Selassie failed to gain any wide support for Ethiopia until Italy declared war on Britain in 1940. With the aid of British troops and volunteers from all over Africa, Ethiopians expelled the Italians in 1941 and Haile Selassie was restored to the throne. In North Africa, the British, Germans, and Italians fought a hugely destructive war across the deserts of Libya and Tunisia until 1943. African volunteers from British- and French-controlled areas served in the Allied army in Europe and Asia. In the long term, the most significant impact of World War II on Africa was political and psychological. The brief colonization and subsequent liberation of Ethiopia had galvanized the emerging class of urban, educated Africans. These people were determined that the war--fought and won in the name of freedom--should liberate them too. Throughout the continent, from Algeria to Ghana to South Africa, Africans awoke with a new determination to bring an end to the humiliation of colonization. P The Winning of Independence After World War II the dominant African colonial powers, France and Britain, were too economically weakened to resist African demands for political reform. They hoped, however, that even as they loosened their political grip upon the continent, the colonial economic subservience of Africa to Europe could be maintained. P1 North Africa In some parts of North Africa, independence came fairly quickly and smoothly after the war: Libya became independent in 1952, and both Morocco and Tunisia in 1956. Meanwhile, in Algeria, the numerous and powerful French colonists were determined that it would remain part of France. The bitter and bloody Algerian War of Independence was fought until the French finally conceded independence in 1962. In Egypt, radical Muslim army officers overthrew the British puppet government in 1952. Led by Gamal Abdel Nasser, they redistributed Egyptian land to the peasantry and nationalized the Suez Canal in 1956. This was the final symbol of Egyptian independence from Europe, and the failure of Britain's attempt to regain the canal signaled to the rest of Africa that the colonial bluff had been called. P2 French Sub-Saharan Colonies In sub-Saharan Africa, the French were quickest with political reform. Across French West Africa and French Equatorial Africa, the French allowed the election of local government representatives and in return received African agreement to maintain close economic ties with France. In 1946 the French established a common West African French currency, the CFA franc (franc de la communauté financière Africaine, or franc of the African financial community). The currency, exchanged at a fixed rate with the French franc, assured that virtually all of France's decolonizing African territories would continue to bank, invest, and trade with France. All of France's subSaharan colonies became independent in 1960, except Guinea (1958) and Djibouti (1977). P3 British Colonies and South Africa The British decolonizing process was more haphazard and often more African-driven in its initiatives. The Gold Coast led the way, becoming independent Ghana in 1957. Thereafter, the pace of liberation of British colonies largely depended on how long it took the population to agree on its leaders and form of government. Most subSaharan British colonies became independent in the period from 1960 to 1964. It was only in the colonies with substantial numbers of white settlers that the process was seriously delayed or fought over. Thus, the Mau Mau Rebellion of the 1950s was required to persuade the British to drop their backing of white settler power in Kenya. The British did little to prevent the white settlers of Rhodesia from declaring the independence of their own white minority regime in 1965. After a decade of guerrilla warfare, Zimbabwe was finally liberated in 1980. White settler power in industrialized South Africa was more entrenched. The white South African government overrode the wave of African nationalism in the 1960s and 1970s by the use of widespread oppression and imprisonment. Through the 1980s internal rebellious pressures combined with the loss of Western support finally prompted the South African government to change. South African-occupied Namibia became independent in 1990, and the government negotiated an end to the oppressive apartheid system with the country's African majority from 1990 to 1994. P4 Belgian Congo Belgium had no plans for decolonizing the Belgian Congo until 1959, when it panicked in the face of rapid political change in surrounding colonies. It rushed toward an ill-prepared decolonization in 1960, with the departing Belgians hoping to retain a measure of economic control by handing political power over to a weak and disunited government. With Belgian prompting, civil war erupted. As the country slid into chaos, the prime minister, Patrice Lumumba, was murdered, while United Nations peacekeeping troops were largely ineffective. Order was only restored in 1965 with the establishment of the brutal military dictatorship of Joseph Désiré Mobutu (later Mobutu Sese Seko). Mobutu's regime was to last until 1997 when, following his overthrow, the country once more slid into a state of civil war. P5 Portuguese Colonies The liberation of Portugal's colonies of Guinea-Bissau, Angola, and Mozambique was only achieved after lengthy and bitter guerrilla wars. Exhausted, Portugal withdrew from its colonies in 1974 (in Guinea-Bissau) and 1975 (in Angola and Mozambique), leaving behind revolutionary Marxist regimes to attempt to transform battered economies. Instead, Angola and Mozambique became pawns in the Cold War, as South Africa and the United States supported rebel armies in both countries in the name of fighting communism. These external pressures were not lifted until the late 1980s. Even then, Angola's civil war continued for another decade. Q Africa into the 21st Century Africa's political inheritance from colonial rule was a mass of artificial "nations" with arbitrarily drawn borders and ethnically diverse populations with few or no historical ties. In the buildup to independence, "nationalism" presented only a façade of unity in the face of the colonial opponent. After independence that unity only survived while the new African government was able to deliver on its promise to improve the lives of its citizens, particularly in terms of employment and social services. The colonial powers had been at pains to emphasize ethnic diversity, as a way to weaken national opposition. They had encouraged a sense of ethnic difference and rivalry far greater than that which had existed in precolonial times. In the most extreme version of this policy, for instance, the German and Belgian rulers of Rwanda and Burundi had encouraged Hutu and Tutsi adversity. They co-opted the Tutsi aristocracy as their partners in colonial rule and, in doing so, deprived the Hutu peasantry of educational and economic opportunities. In this policy lay the seeds of Hutu-Tutsi ethnic hatred that was to lead to massacres and genocide in the 1990s. In many democratic nations of independent Africa, political parties developed around ethnic identity. As a result, insecure governments constantly feared ethnic conflict or secession. The fear was well founded, as shown by the 1967 secession of the Igbo homeland, called Biafra, from Nigeria, leading to the Nigerian Civil War (19671970). Q1 Political Development in Independent Africa In the 1960s fear of divisive tendencies encouraged many African governments to set up one-party states, in which it was argued that the entire population could work together for the common good of development. In practice, this allowed weak governments to become dictatorial in order to stay in power. In many of these cases, the country's military responded by intervening and seizing power by force. In the first decades of independence, military intervention was often welcomed by urban populations who felt betrayed by weak civilian governments tainted by corruption and failed economic schemes. Military governments proved no better, however, and they too supported themselves by corruption. Many grew even more brutally dictatorial and, unrestricted by constitutional rule, committed atrocities against their perceived opponents. Among the most extreme examples were the rules of Idi Amin of Uganda and Jean-Bédel Bokassa of the Central African Republic, both overthrown in 1979. Through the 1980s many dictators were kept in power by external support, usually in the name of Cold War politics. It was not until this support was withdrawn around 1990, at the end of the Cold War, that most African people had the chance to demand accountable governments. From 1990 to 1994 most countries established or reestablished multiparty systems of elective government. Citizens voted long-standing autocratic governments out of office in countries such as Niger, Mali, Malawi, and Zambia, while the more astute military rulers, such as Jerry Rawlings of Ghana, discarded their uniforms and were elected as civilian presidents. Several African countries went against the trend of ousting dictatorial and military governments in favor of multiparty democracy in the first half of the 1990s. The scale of military corruption in oil-rich Nigeria delayed the process until the late 1990s. Mobutu's 1997 overthrow by armed rebellion created the instability that slid the Congo into outright civil war in the late 1990s and early 21st century. In Algeria, when it appeared that a militant Islamist party was about to win 1992 legislative elections, the Algerian military cancelled the election, suspended the legislature, and ushered in a decade of violent civil conflict. In Libya, the long-standing one-party regime of revolutionary leader Muammar al-Qaddafi ruled on, supported by huge oil wealth, reasonably redistributed among a sparse population. Although a new era of accountable government arrived in Africa in the 1990s, it is still very unstable, and military coup d'états still occur. Nevertheless--as in the cases of The Gambia, Sierra Leone, and Niger in the mid- or late 1990s--an incoming military ruler now has to justify his presence by declaring that he is only there temporarily to right some specific wrongs and to reestablish civilian democracy within a very short timespan. Africa no longer tolerates indefinite dictatorships. However, the proliferation of weapons across the continent, economic hardship, and weak government infrastructures have combined to encourage banditry and civil conflict across much of Africa. In West Africa, a violent civil war in Liberia in the 1990s spilled over into Sierra Leone, where it continued long after peace returned to Liberia. Even Côte d'Ivoire--long a model of stability--has not been immune from violent conflicts. At least, however, African governments have taken up a collective sense of responsibility and are prepared to intervene on a regional basis to settle disputes or even to restore peace and order. Q2 Africa and the World Economy Africans are faced with widespread poverty, ill health, and lack of educational opportunities. Despite the positive political developments of the late 20th century, many African governments have been unable to improve their peoples' standards of living. The foundation of Africa's disadvantaged position has been its economic role in the world trading system. Since at least the mid-19th century African economies were increasingly reworked to meet the needs of industrial Europe. Virtually all economic infrastructure was geared toward the export of Africa's raw materials to Europe. Economic transaction and communication between neighboring states stopped if they were ruled by different colonial powers. African manufacturing was discouraged, and even banned, if it was likely to compete with the interests of European manufacturers. Indigenous African industry dwindled, and Africa was forced to import virtually all of its manufactured consumer goods. This was the economic system that Africa inherited at independence. Making Africa even more dependent, the prices paid for its exported raw materials were set in the major financial markets of the world: New York City, London, Paris, Frankfurt, Hong Kong, and Tokyo. The prices on African commodities rose and fell according to the needs of the industrial world, bearing no relationship to the costs of production or the economic needs of Africa. The full implications of this were powerfully demonstrated during the energy crisis of 1973. As oil prices quadrupled, the Western world went into recession and African commodity prices tumbled. Although North African oil producers benefited, sub-Saharan Africans were not yet oil producers on a significant scale and they too suffered from the hike in oil prices. The industrial world paid less and less for African commodities, while at the same time demanded higher and higher prices for its manufactured goods, which Africans needed to import. In this way Africa helped subsidize the industrial world's economic recovery while most African countries spiraled into debt, poverty, corruption, and political instability, from which they have spent decades trying to recover. Since the 1980s the industrial world's financial tools, the International Monetary Fund (IMF) and the International Bank for Reconstruction and Development (World Bank), have proposed solutions to Africa's chronic indebtedness. These solutions have been based upon the economics of developed economies, however, rather than upon the specialized needs of developing countries. They have directed African development plans to increase raw material exports, in order to generate the foreign exchange to pay back Africa's debts. But as Africans export more coffee, for example, the price of coffee falls. Thus, Africans work harder and receive less for their efforts. The ultimate goal of the IMF and World Bank has been to enable Africa to pay its debts rather than to enable Africa to develop the self-sufficient ability to compete on equal terms with the industrialized world. They have succeeded in their goal: Africa pays back more in debt servicing than it receives in direct aid. But this means that governments have less to spend on health and education, leading to falling living standards. African leaders are striving to establish regional trading groups to strengthen their position in the global market. In 2002 they inaugurated the African Union, an organization intended eventually to establish a common economic market and political union across the entire continent. Achieving this goal, which would make Africa a formidable world power, remains Africa's primary task for the 21st century. The History section of this article was contributed by Kevin Shillington. Contributed By: James L. Newman Assefa Mehretu Kevin Shillington Robert Stock Microsoft ® Encarta ® 2009. © 1993-2008 Microsoft Corporation. All rights reserved.

« The highest elevations in Africa are found in the various ranges of East Africa.

After Kilimanjaro, the next highest peaks are Mount Kenya (5,199 m/17,057 ft), north ofKilimanjaro in central Kenya; Margherita Peak (5,109 m/ 16,762 ft) in the Ruwenzori Range on the border between Uganda and the Democratic Republic of the Congo(DRC); Ras Dashen (4,620 m/ 15,157 ft) in the Ethiopian Highlands of northern Ethiopia; Mount Meru (4,565 m/ 14,977 ft), close to Kilimanjaro in Tanzania; and MountElgon (4,321 m/ 14,177 ft) on the Uganda-Kenya border. Africa’s other major mountainous regions occur at the northern and southern fringes of the continent.

The Atlas Mountains, a system of high ranges, extend for 2,200km (1,400 mi) across Morocco, Algeria, and Tunisia, roughly parallel to the northern coast.

These ranges enclose a number of broad inland basins and plateaus.

In thewest, the High (or Grand) Atlas contains Toubkal (4,165 m/ 13,665 ft), the highest peak of the system.

Toward the east, the Atlas consists of two parallel ranges: theTell Atlas to the north and the Saharan Atlas to the south. In southern Africa, the U-shaped Great Escarpment extends 5,000 km (3,000 mi) along the coast from Angola to Mozambique (an escarpment is a ridge that is steep on one side and slopes down gently on the other).

The Drakensberg Mountains form the most pronounced relief of the Great Escarpment, rising to 3,482 m (11,424 ft) atThabana Ntlenyana in Lesotho. Cameroon Mountain is the highest peak in West Africa at 4,095 m (13,435 ft).

To the north, isolated highlands occur in the desert land of the Sahara, including theAhaggar Mountains in southern Algeria and the Tibesti in northern Chad. A1 b Great Rift Valley The Great Rift Valley is one of the most distinctive features of African topography.

Formed where Earth’s crust is being pulled apart by the action of convection currentsbeneath the surface, rift valleys are long, deep valleys bounded by parallel faults, or fractures, in Earth’s crust.

The Great Rift Valley system begins in Syria, in theMiddle East, and extends southward, down the length of the Red Sea.

It enters Africa at the Afar Depression on the coast of Eritrea and Djibouti, and winds some 5,600km (3,500 mi) to the coast of southern Mozambique.

In its middle section, it breaks into two major branches, the Eastern Rift Valley and the Western Rift Valley.

The riftvalley is flanked by towering escarpments of up to 1,000 m (3,000 ft) in southern Ethiopia, 1,500 m (4,900 ft) along the Eastern Rift in central Kenya, and 1,300 m(4,300 ft) in the northern part of the Western Rift, along the DRC’s border with Uganda, Rwanda, and Burundi.

The southern extremities of the rift system are muchless spectacular in size and appearance.

For more information, see the Faulting and Rift Valleys section of this article. Several major lakes, typically long and narrow, are located on the floors of the Western and Eastern rift valleys.

The Western Rift contains Lake Albert, Lake Edward,and Lake Kivu to the north, Lake Tanganyika in the middle, and Lake Malawi (Lake Nyasa) to the south.

The lakes of the Eastern Rift tend to be smaller and includeLake Naivasha, Lake Natron, and the southern part of Lake Turkana. A1 c Deserts The Sahara is the world’s largest desert.

It stretches from the Atlantic Ocean to the Red Sea, and from the Mediterranean Sea and Atlas Mountains southward for 2,000km (1,000 mi) until it merges imperceptibly into the semidesert Sahel region.

Most of the desert consists of extensive plains covered with loose gravel and boulders,called reg.

The rest of the desert is made up of areas of shifting sand dunes, called erg, interspersed with stretches of bare, rocky areas called hamada . The Namib and Kalahari deserts of southern Africa are much smaller than the Sahara.

The Namib Desert stretches along the Atlantic coast for 1,500 km (930 mi) fromsouthern Angola along the entire length of Namibia, and into western South Africa.

The nearby Kalahari Desert, in Botswana, Namibia, and South Africa, is a semiaridregion in the center of the Kalahari Basin. A1 d Coastline Generally, Africa’s coastline is very even, with few good natural harbors.

The coastal plain is narrow around much of the continent, particularly in the south and east.Major escarpments run parallel to the coast in several areas.

Most of the Red Sea and Indian Ocean coastline is fringed by coral reefs, which are an obstacle to ships.On the Atlantic coast, waters are generally too cold for coral development.

Africa’s best natural harbors are found in the many deep coastal inlets between Senegal andLiberia, especially at the mouths of rivers.

Lagoon coasts, with a coastal barrier beach backed by lagoons, are common between Liberia and Nigeria. A2 Formation of Africa Scientists use the theory of plate tectonics to explain the formation of Africa and the other continents.

According to this theory, the crust of Earth’s surface consists of acollection of 14 rigid plates floating on an underlying mantle.

These plates are in constant motion—moving apart, colliding, and thrusting beneath one another.

Africa sitsat the center of the African Plate, one of the largest of Earth’s plates. For much of Earth’s history, the land made up one vast supercontinent known as Pangaea.

About 220 million years ago, tectonic activity broke Pangaea apart into thesupercontinents of Gondwanaland and Laurasia.

Gondwanaland subsequently broke apart as well: First Antarctica, Australia, Madagascar, and the Indian subcontinentbroke away, followed by South America.

Africa, at the core of Gondwanaland, assumed roughly its present-day shape about 15 million years ago when the formation ofthe Red Sea split off the Arabian Peninsula. A3 Geological Structure The geological structure of Africa is very complex, reflecting many stages and types of development over a period of 3.5 billion years.

Most of the continent consists ofrock dating from the Precambrian Period (more than 570 million years ago).

These rocks are either igneous rocks such as granite or metamorphic rocks such as schist,gneiss, and quartzite.

These ancient rocks—along with some slightly younger sedimentary rocks such as sandstone and limestone—make up what is called the basement complex of the African continent. In much of the continent, younger deposits of igneous and sedimentary rock were laid down on top of the basement complex.

The largest of the sedimentary depositsformed in northern and western Africa during the Paleozoic Era (between 570 million and 240 million years ago).

Later in the Paleozoic, sediments were deposited inparts of present-day South Africa.

In the Mesozoic Era (between 240 million and 65 million years ago) this area was also covered with igneous basalt from major lavaflows.

Sedimentary limestone was deposited during the Mesozoic on Africa’s northern edge.

More recent sedimentary deposits dating from the Cenozoic Era (from 65million years ago to the present) occupy the bottoms of the continent’s large, shallow interior basins and some coastal areas. A4 Geological Evolution Africa contains three major cratons, or areas of basement-complex rock that have been geologically stable for hundreds of millions of years.

The Kalahari craton is located in southern Africa, the Congo craton is in Central Africa, and the northwest African craton, forming the core of West Africa, is centered in the western Sahara.. »

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