Connections across a wide region

One of the most fascinating stories in the history of agriculture involves the Bantu migrations across the sub-Saharan regions of Africa. This is a part of the world whose people passed information down through a rich oral tradition, but left very little in writing until the Middle Ages. Researchers have found ways to trace the movement of Bantu-speaking peoples that began possibly as early as 2000 BCE. Evidence suggests that they moved rapidly across the continent, south and east, sometime between 2000 BCE and 1000 CE. By about 1200 CE, “Bantu-ness” was a cultural and technological network across the vast trunk of Africa. Bantu expansion reached almost all the way to the southern tip of the continent. The result was a great web of trade, cultural exchange, and shared technology across this wide region.

One reason the movements of ancient West African peoples are so fascinating is the timing. The agricultural revolution that transformed much of Afro-Eurasia starting at about 8,000 to 10,000 years ago seems to have begun much later in most of sub-Saharan Africa. But why? Cattle herding emerged as an early technology in northern Africa—perhaps earlier than anywhere else in the world—yet farming seems to have come much later. We do have some evidence of farming in the northwestern area of modern-day Cameroon— originally home to Bantu-speaking peoples—as early as 7000 BCE. Foragers, however, seem to have dominated most of the other regions until at least 2000 BCE. Archaeologists have unearthed pottery, iron tools, and settlements—all pretty good evidence of agriculture.

These artifacts radiated south and east from the Bantu homeland and date to between 2000 BCE and 1000 CE. These technologies, along with the agricultural and pastoral people that used them, then spread out across most of Africa. (Yes, pottery and iron tools are technologies.) But why and how did these technologies move to create this vast network across the continent?

Evidence from different academic disciplines

Maps of the Bantu migrations, like the one above, appear frequently in history books and on the Internet. Their bright arrows show a path of Bantu-speaking peoples moving south along the coast and east along the Congo and Zambezi rivers. These routes finally converge on the southeast coast of the continent. But on closer examination, the arrows are often very general, and different maps often show different pathways. It’s hard to know what information is reliable. The good news is that there is excellent evidence for the movement of Bantu technologies and culture. It comes from a variety of disciplines and types of sources.

Let’s look at the northwestern region of modern-day Cameroon among the ancient settlements of Bantu-speaking populations of western Africa. Here, archaeologists have found potsherds (pieces of broken pottery) dating back to 5000 BCE. Since pottery-making is associated with sedentary lifestyles, this evidence supports a theory that sub-Saharan agriculture could have begun in this region. T. N. Huffman, an archaeology professor in South Africa, clarifies that “Ceramic style can be used to recognize and trace the movements of people” (Huffman 108). Archaeologists analyze the age of potsherds found at other dig sites throughout the continent. That creates data that can be used to map the spread of agriculture. We can see where it started in western Africa, and then how it radiated out in two distinct directions, south and east.

Meanwhile, researchers in the field of linguistics have gathered their own evidence about the spread of the Bantu language. Linguists analyze modern Bantu-based languages, like Swahili. That is, rather than using ancient pieces of pottery, this discipline looks at how people speak right now to find clues about the past. They work to establish a chronology for the development of various branches along the Bantu language tree. Although culture can spread from one place to another through ideas and technology, language spreads with the physical movement of people speaking it. That’s why linguists theorize that the Bantu-speaking peoples of western Africa migrated south and east, between 2000 BCE and 1000 CE. K. Rexova, a linguist in the Czech Republic, has suggested that “A fairly homogenous population of Bantu speaking people had spread from the northwest of the equatorial forest in Cameroon and Nigeria throughout central, eastern and southern Africa” (Rexova 189).

More recently, geneticists have used some new techniques to analyze the DNA of modern speakers of Bantu languages, like Swahili in southeastern Africa. Geneticists then determine which populations share genetic code with the original Bantus of western Africa. That data enables them to compare the percentages of shared code among all the modern peoples in the region. Using this information, researchers have been able to develop a chronological family tree. Carlotta De Filippo, an Italian geneticist confirms that, “Our analyses primarily indicate that the dispersal of Bantu languages was coupled with the movement of people, as demonstrated by the lower genetic distances among Bantu populations when compared with those between Bantu and all the other major ethno-linguistic groups” (De Filippo 3262). The evidence has led her and other geneticists to theorize that Bantu- speaking people left western Africa and migrated south and east over a period of a couple thousand years between 2000 BCE and 1000 CE. And in case you forgot what happened in the last paragraph, the linguistic evidence showed the same thing! That means both genetic and linguistic evidence seem to support what archaeologists believe about the spread of agriculture through sub-Saharan Africa.

Theories about the Bantu migration

All of this evidence, however, raises at least as many questions as it answers. Bantu migration is a puzzle, but to study it opens a terrific discussion about the movement of people, technology and culture in these ancient times. How did the vast Bantu network that we see across the trunk of the continent by 1200 CE actually come into being? Three theories have emerged: migration, adoption and diffusion. They aren’t mutually exclusive—they may all be right to a certain extent—but they are quite different.

There are still disputes about which of these theories is correct, or how they might all be part of the same story. Genetic evidence, for example, might suggest that migration occurred at a high rate in a particular location. In contrast, archaeological evidence might support the adoption or rejection of Bantu technology in a nearby location. But there are still many more questions to answer.

Table 1: Theories about the Bantu Migration

More questions to answer

The story of the agricultural revolution in sub-Saharan Africa is incomplete. Based on evidence from multiple academic disciplines, theorists continue to debate the migration routes of Bantu-speaking farmers from western Africa. Some even question whether they migrated at all. Why, for instance, did Bantu farmers move from their homeland while their foraging ancestors did not? Was it as Leonard Ngcongco of the University of Botswana has suggested, that “people move … for a reason. They move because the population has expanded. They move because the resources which support the population in the settlements have become more or less inadequate. They move because there are changes to the climate and they move for the sake of finding better areas in which to live” (BBC).

What seems certain is that farming in the region began near the modern-day border of Cameroon and Nigeria somewhere between 5000 and 2000 BCE. Eventually farming replaced foraging as far away as the Swahili Coast by about 1000 CE. Beyond that, researchers can only debate. Perhaps historians, along with archaeologists, linguists, geneticists and other researchers, will find answers to these questions as new evidence emerges. Once these scholars assemble their conclusions into a single cohesive theory, it may help explain the spread of agriculture and language across the African continent.