Africa is a large continent, almost 12 million square miles or about three times the size of the United States. Most of it lies in the tropics and, although we often think of Africa in terms of its rain forests, less than ten percent of the continent is covered by tropical forests, and those are mostly in West Africa.

Much of the African surface is covered by savannas, or open grasslands, and by arid plains and deserts.

In geological terms, the continent is really formed by a series of high plateaus broken in the east by the Great Rift valley and the mountains that surround it. Large rivers - the Congo, the Nile, the Zambezi, and the Niger - begin in the interior of the continent and flow to the sea over great falls and cataracts that mark the passage from the plateau to the coast.

These falls have historically made movement from the coast to the interior difficult, but the great river systems have also provided the interior of Africa with routes of communication.

We have already noted the origins of humankind in East Africa (Olduvai Gorge, Tanzania), where some of the earliest fossil remains of protohominids have been found. Even before the appearance about 300,000 years ago of Homo sapiens, the ancestors of modern human beings, other hominid species, such as Homo erectus, had moved outward from Africa to Asia and Europe.

Africa, therefore, holds a special place in the development of the human species. It was the scene of human origins. Moreover, in cultural terms, Africa participated in the early development of civilization.

Despite the false image of Africa as the "dark” and isolated continent, it was, in fact, often in contact with other areas of the world. It received from them technology, crops, ideas, and material goods that in turn stimulated social and cultural innovations.

Moreover, the contacts were not always in the same direction, and there is now considerable evidence that not only early humans but also certain languages, crops, political, and cultural influences spread outward from Africa.

It is useful to begin this account by noting the climatic change that altered the appearance of the African continent and seems to have set a whole series of historical processes in motion. That change centers on the area of the Sahara, which during the Late Stone Age appears to have been far better watered than it is today, receiving between 10 and 50 times as much rain as at present. 

Archeological evidence indicates that a number of peoples, such as the ancestors of the modern-day Berbers and Tuaregs of North Africa, who speak languages related to ancient Egyptian, and the ancestors of the Negro peoples of sub-Saharan Africa, some of whom also spoke these Afro-Asiatic languages and others who did not, inhabited the area of the Sahara during this period.

Around 9000 years ago this situation began to change as temperatures rose and rainfall became erratic. By about 3000 B.C., much of the area was desert. The droughts that have recently affected Africa indicate that the desiccation, or drying up, of the Sahara is continuing and the desert is growing.

As the Sahara became less habitable, the populations moved north toward the Mediterranean coast and south into the area of the dry Sahel, or fringe, and, especially, onto the grassy savannas suitable for agriculture and grazing. Savannas stretch across Africa from the mouth of the Senegal River on the west coast to Lake Chad and the Upper Nile valley.

This broad region, the Sudan, became a center of cultural development. The movement of peoples into the Sudan and toward the Nile valley and the Mediterranean, set the stage for major developments in the subsequent history of Africa.

Agriculture, Iron, and The Bantu Peoples

Agriculture may have developed independently in Africa, but many scholars believe that the spread of agriculture and iron throughout Africa linked that continent to the major centers of civilization in the Near East and Mediterranean world. The drying up of the Sahara had pushed many peoples to the south into sub-Saharan Africa. 

These were the ancestors of the Negro peoples. They settled at first in scattered hunting-and-gathering bands, although in some places fishermen near lakes and rivers, with a more secure food supply, lived in larger population concentrations. 

Agriculture seems to have reached these people from the Near East, since the first domesticated crops were millets and sorghums whose origins are not African but West Asian. The route of agricultural distribution may have gone through Egypt or Ethiopia, which long had contacts across the Red Sea with the Arabian Peninsula. There is evidence of agriculture prior to 3000 B.C.

Once the idea of planting grew, Africans began to develop their own crops, such as certain varieties of rice, and they demonstrated a continued receptiveness to new imports. The proposed areas of the domestication of African crops lie in a band that extends from Ethiopia across the southern Sudan to West Africa.

Subsequently, other crops, such as bananas, were introduced from Southeast Asia, and in the 16th century A.D. American crops, such as maize and manioc, spread widely throughout Africa.

Livestock also came from outside Africa. Cattle were introduced from Asia, as probably were domestic sheep and goats. Horses were apparently introduced to Africa from West Asia by the Hyksos invaders of Egypt (1780-1560 B.C.) and then spread across the Sudan to West Africa.

Rock paintings in the Sahara indicate that horses and chariots were used to traverse the desert and by 300-200 B.C. there were trade routes across the Sahara. 

Horses were adopted by peoples of the West African savanna, and later their powerful cavalry forces allowed a number of them to carve out large empires. Finally, the camel was introduced from Asia around the first century A.D.

This was an important innovation, because the camel’s ability to thrive in harsh desert conditions and to carry large loads cheaply made it an effective and efficient means of transportation. The camel transformed the desert from a barrier into a still difficult, but more accessible, route of trade and communication.

Livestock provided a living to peoplesin the arid portions of the savanna belt and the Sahara, and permitted a nomadic or seasonally moving, or transhumant, way of life to flourish in certain inhospitable regions. In some areas, it appears that livestock and agriculture arrived about the same time.

The spread of cattle was seriously limited in some places by the tsetse fly, which carries a disease (sleeping sickness) dangerous to humans and especially cattle. The tsetse flourished in wet lowlands below 350 0 feet, and it severely limited pastoralism and also the use of animals for farming and transport as a way of life.

Iron also came from West Asia, although its routes were somewhat different from those of agriculture. Most of Africa presents a curious case in which societies moved directly from a technology of stone to iron without passing through the intermediate stage of copper or bronze metallurgy, although some early copper-working sites have been found in West Africa. Iron had been worked in the Near East and Anatolia for at least a thousand years before it began to penetrate into sub-Saharan Africa. 

The Phoenicians carried the knowledge of iron smelting to their colonies, such as Carthage in North Africa, and from there to their trading ports along the coast of Morocco. 

By sea down the coast or by land across the Sahara, this knowledge penetrated into the forests and savannas of West Africa during the thousand years before Christ, or at roughly the same time that iron making was reaching western Europe. Evidence of iron making has been found in Nigeria, Ghana, and Mali, and iron implements seem to have slowly replaced stone ones at a number of sites.

This technological shift caused profound changes in the complexity of African societies. Iron represented power. In West Africa the blacksmith who made tools and weapons had an important place in society, often with special religious powers and functions. Iron hoes, which made the land more productive, and iron weapons, which made the warrior more powerful, had symbolic meaning in a number of West African societies. Those who knew the secrets of iron making gained ritual and sometimes political power.

Iron entered Africa by other routes as well. Iron making seems to have traveled from the Red Sea into Ethiopia and East Africa and down the Nile from Egypt into the Sudan where large African states, such as Meroe (Kushite kingdom), were in close contact with dynastic Egypt. Meroe’s contact with peoples to the south led to the further diffusion of iron technology. 

By the first century A.D., iron was known in sub-Saharan Africa, and within about a thousand years it had reached the southern end of the continent. Iron tools and weapons increased efficiencies in agriculture and war. The adoption of agriculture and the use of iron tools and weapons were roughly simultaneous processes.

Unlike in the Americas, where metallurgy was a very late and limited development, Africans had iron from a relatively early date, developing ingenious furnaces to produce the high heat (1100 f) needed for production and to control the amount of air that reached the carbon and iron ore necessary for making iron. 

Except for those regions directly influenced by the great Bronze Age civilization of Pharonic Egypt, much of Africa skipped right into the Iron Age, taking the basic technology and adapting it to local conditions and resources.

The working of bronze was also known to Africans and by A.D. 1000 remarkably lifelike bronze sculptures of great technical virtuosity were cast at the city-state of Ife in Nigeria by the Yoruba people.

The Bantu

The diffusion of agriculture and later of iron was accompanied by a great movement of people who may have carried these innovations. These people probably originated in eastern Nigeria in West Africa. Their migration may have been set in motion by an increase in population caused by a movement into their homelands of peoples fleeing the desiccation of the Sahara. 

They spoke a language, proto-Bantu (bantu means "the people”), which is the parent tongue of a large number of related Bantu languages still spoken throughoutsub-Saharan Africa. In fact, about 90 percent of the languages south of a line from the Bight of Benin on the west coast to Somalia on the east coast are part of the Bantu family.

Why and how these people spread out into central and southern Africa remains a mystery, but archeologists believe that at some stages their iron weapons allowed them to conquer their hunting-and-gathering opponents, who still used stone implements. Still, the process is uncertain, and peaceful migration - or simply rapid demographic growth - may have also caused the Bantu expansion.

The migrations moved first to the central Sudan and then into the forests of West and central Africa. The rivers, and especially the Congo basin, provided the means of movement; the migration was a long, gradual, and intermittent process. 

From the study of the related Bantu languages, it is possible to learn something about the original culture of the proto-Bantu speakers. The early Bantu depended on agriculture and fishing. They raised goats and cattle. They were village dwellers who organized their societies around kinship ties.

Leadership of the villages was probably in the hands of a council of elders. The spirits of the natural world played a large role in the lives of these people. They looked to their ancestors to help deal with those spirits, and depended on village religious specialists to deal with calamity and to combat witchcraft, which they greatly feared.

By that time, Black Africa’s major features were in place. A few pure hunting peoples remained, such as the Pygmies of central Africa, but their way of life was not that of most Africans. Agricultural and herding societies with knowledge of iron metallurgy could be found throughout sub-Saharan Africa. 

While pockets of peoples still speaking non-Bantu languages existed, such as the Khoi-Khoi and Bushmen of southern Africa, and in East Africa the influence of Ethiopian culture was stillstrong, Bantu languages predominated all over southern and central Africa and marked the trail of one of the world’s great migrations.

The writer is a Vice Chancellor at the African Leadership University in Kigali.