15.1.1 African Geography, Migrations, and Settlement

North of the Sahara is a thin strip of forest and scrubland hugging the southern shores of the Mediterranean Sea. Like other parts of the Mediterranean world, it has a relatively mild climate with sufficient rainfall, wet winters, and dry summers. For this reason, the arable land there is suitable for growing grains like wheat and barley, originally domesticated in the Fertile Crescent and disseminated around the sea over thousands of years. Likewise, this northern African region has had a long history of cultural contact with other Mediterranean cultures like the Greeks, Phoenicians, and Romans. As a result, the cultural practices, religions, and languages of the larger Mediterranean world have had, and continue to have, a huge impact on this region.

South of the Sahara is the Sahel, a semiarid belt of land that separates the desert in the north from the savanna in the south. The Sahel is a transitional zone that stretches some 3,300 miles across the continent. The farther south, the longer is the rainy season (four months on average), the more temperate is the climate, and the greater is the abundance of pasturage and forage plants for livestock (especially cattle and sheep), including grasses, thorny shrubs, and baobab trees. The word Sahel is derived from the Arabic sahil, meaning “shore.” This is a reference to the view held by many that the Sahara was a vast sea of sand that could be navigated only with great difficulty.

The Sahara’s extremely dry conditions are hostile to both plants and animals, so only small-scale human settlements are possible. These are clustered around the desert’s oases, which amount to a fraction of a percentage of its total landmass. During the Middle Ages, these oases were crucial hubs connecting trade routes across the desert, nowhere more so than in West Africa, where medieval kingdoms competed for control over markets and the movement of goods across the region.

During the medieval period, the Sahara provided powerful West African kingdoms with a vital commodity: salt. Almost completely unobtainable in the inland regions south of the Sahara, salt was mined from sites such as Taghaza and transported in enormous slabs on the backs of camels in caravans that crossed the desert to West African villages and beyond (Figure 15.4). Salt became the second most prized good traded across the Sahara—the first being gold. Indeed, salt was such a valuable commodity that the king of Ghana stored it in the royal treasury alongside gold nuggets.

The southern frontier of the Sahel is marked by the transition to grasslands and tropical woodlands of the savanna. While the Sahara is dry and arid, the savanna is more temperate and wetter, carpeted with grasses and studded by scattered trees. At its extreme end near the West African rainforests stretching from modern-day Sierra Leone to Ghana, the savanna can see as much as forty-eight inches of rain per year (the rainy season lasts from May to October), which is similar to the average annual rainfall of New York City in the United States. Alongside a greater abundance of vegetation, the savanna is also home to a wider range of wildlife, including cattle, antelope, and giraffes. Endowed with a hospitable environment, climate, and geography, the plains of the savanna have historically been the region with the greatest concentration of human settlement in Africa.

Winding through the savanna and Sahel regions of West Africa is the Niger River. Along its fertile banks, people have grown staple crops like sorghum, African rice, and millet for hundreds of years. Approximately 2,500 miles in length, the Niger is West Africa’s longest river. It was critical to the development of medieval West African kingdoms, both for its ability to sustain intensive agriculture and as a crucial transport conduit for goods and commodities (Figure 15.5). It was in the areas drained by the Niger River where West Africa’s great empires emerged, profiting from the flows of salt from the north and gold from the south. In this way, these empires grew fabulously wealthy.

To the south of the savanna lies the tropical rainforest, Africa’s third major environment alongside the desert and the savanna. Relative to the Sahara, the African rainforest covers a far smaller geographic footprint: some two million square miles, or roughly 10 percent of the continent’s total landmass. Nevertheless, the rainforest is rich in biodiversity, including pygmy hippopotamuses, giant forest hogs, canopy monkeys, and chimpanzees, as well as thousands of species of plants. In West Africa, dense stretches of rainforest can be found in Sierra Leone, Liberia, and Côte d’Ivoire. In this area, the Bantu initially encountered the Nok people, from whom they acquired the metallurgical knowledge that enabled them to move into and later emerge from the equatorial rainforest between 500 and 1000 CE. The gradual dispersal of the Bantu throughout much of southern Africa followed.

Bantu speakers had been migrating from this area possibly since as early as 3000 BCE. But with the adoption of ironworking technology from the Nok, these ironworking farmers were able to travel throughout much of the eastern, western, and southeastern regions of the subcontinent. Their Iron Age economy was dominated by farming, mostly of sorghum and millet, with some livestock including cattle, pigs, and chickens, although animal husbandry tended to be secondary to farming. Because the regions into which they moved were only thinly populated by roving bands of hunter-gatherers, the Bantu were able to choose the most suitable land for farming. Early Iron Age Bantu settlements tended to be small, typically consisting of a dozen or so round houses encircling a livestock pen of cattle or goats. Larger settlements (sometimes in the range of several hectares) could be found in regions such as Natal, favored by large Bantu kinship groups because of the combination of rich biodiversity and sparse population. Settlements were placed close to iron ore and wood for the smelting of carbon steel. The early Iron Age Bantu economy necessarily focused on self-sufficiency with little potential for trade, although some small-scale trade did take place, particularly of sought-after commodities like copper and salt in regions of the Congo and Tanzania.

Until about the eighth century CE, the Bantu developed and exploited the resources of the more favorable areas and adapted the local environments. Throughout, they remained a stateless society organized along kinship lines. Women tended crops, prepared food, and minded the smaller children, while men tended livestock, hunted for meat and for animal skins for clothing, and engaged in trade with other villages. Women leaders were the exception; archaeological evidence of male dominance is considerable. Authority was decentralized in any case, with no rigidly hierarchical power structure to exercise central authority.

From the tenth century, relatively powerful Bantu kingdoms began to appear in the savanna to the south of the Central African rainforest, and in the plateau between the Zambezi and Limpopo Rivers in the interior of southern Africa. Their large settlements displaced the region’s earlier inhabitants. This revolution in the ancient African political landscape was the combined result of the introduction of Neolithic cultivation and animal husbandry on the one hand, and the adoption of Iron Age technologies, tools, and weapons on the other. The succession of medieval Bantu kingdoms that emerged dominated these regions economically, politically, and culturally.

Migrating originally from West Africa, the Bantu would have recognized much of the geography and climate of southern Africa: there is desert, such as the Kalahari and Namib in southwest Africa, and vast savanna. Entire regions of the modern countries of Angola, Democratic Republic of the Congo, Zimbabwe, Zambia, Tanzania, and Mozambique are blanketed by grassland, as is a large area that extends from southern Mozambique into northeastern South Africa. Both the vegetation and wildlife of the southern African savanna resemble that of West Africa in many ways. The southern African climate also has much in common with that of West Africa, encompassing everything from semiarid to temperate zones, with each experiencing varying amounts of rain. Broadly speaking, the eastern area of the region (including Mozambique and eastern South Africa) is wetter than the western area. The west is sapped of moisture, in part by the Atlantic Ocean’s cold Benguela Current. The resulting dryness of western South Africa was a key factor in the development of the Kalahari and Namib Deserts (Figure 15.6).

Throughout the Middle Ages, the river systems of southern Africa were exploited by the large civilizations developing there. For example, the Limpopo River basin spreads across the southern reaches of today’s Mozambique and Zimbabwe, the northern extreme of South Africa, and the eastern edge of Botswana. The basin’s temperate climate and well-watered landscape encouraged the migration of San hunter-gatherers from southwestern Africa and the settlement of Bantu peoples. The Bantu, who arrived from the north, brought with them the knowledge of ironworking, farming, and livestock herding they had acquired over generations of migrations throughout sub-Saharan Africa. From the tenth century onward, they used this knowledge to cultivate farms across extensive field systems along the basin and to accumulate large herds of cattle.

As the settlements around the Limpopo River grew, so too did the need to manage the basin’s resources and govern the affairs of the people there. As a result, centralized systems of governance emerged among the Bantu peoples in the region, particularly in the Iron Age culture of Leopard’s Kopje in Zimbabwe. This cattle-keeping culture, whose name derived from the site where it was identified (kopje means “small hill”), dominated the area for nearly two centuries, but by the thirteenth century, it had given way to an even larger and more complex state, Great Zimbabwe.