Connections across a wide region

The migration of the Bantu people across sub- Saharan Africa is a fascinating story in the history of agriculture. The Bantu passed information through a rich oral tradition, but left very little in writing until the Middle Ages. Researchers have still found ways to trace the movement of Bantu-speaking peoples that began possibly as early as 2000 BCE.

Evidence suggests that they moved rapidly south and east across the continent sometime between 2000 BCE and 1000 CE. By about 1200 CE, they had a cultural and technological network across the trunk (center) 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.

There was an agricultural revolution in much of Afro-Eurasia starting at about 8,000 to 10,000 years ago. It seems to have begun much later in most of sub-Saharan Africa. It is not known why. There is evidence of farming in modern-day Cameroon, which was originally home to Bantu-speaking people, 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, which are all evidence of agriculture. They date to between 2000 BCE and 1000 CE. These tools spread in the same areas the Bantu did, then spread out across most of Africa. How did these technologies move to create this vast network across the continent?

Evidence from different academic disciplines

There are many maps of the Bantu migrations similar to the one above. The arrows are often very general, and different maps often show different pathways. It’s hard to know what information is reliable, but 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 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. Populations who made pottery typically did not move around. This evidence supports a theory that sub-Saharan agriculture could have begun in this region.

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 who study languages have gathered evidence about the spread of the Bantu language. Linguists analyze modern Bantu-based languages, like Swahili. They try to determine the development of various branches of the Bantu language tree. They can trace the movement of the Bantu people because language spreads with the physical movement of people speaking it.

More recently, scientists who study genetics have used new techniques to analyze the DNA of modern speakers of Bantu languages. They have compared them to the DNA of the original Bantus of western Africa. Their data allows them to see which populations are most closely related to the original Bantus.

Both the linguists and geneticists reached the same conclusion of the archaeologists. They all determined that the Bantu moved south and east from western Africa between 2000 BCE and 1000 CE. 

Theories about the Bantu migration

Bantu migration opens a discussion about the movement of people, technology and culture in these ancient times. How did the vast Bantu network actually come into being? The three theories that have emerged are migration, adoption and diffusion. Migration refers to the physical migration of the Bantu people. Adoption and diffusion refer to the spread of Bantu ideas and technologies.

There are still disputes about which of these theories is correct, or how they might all be part of the same story. For example, the conclusions reached from looking at genetic evidence might differ from the conclusions from archaeological evidence.

Table 1: Theories about the Bantu Migration

More questions to answer

The story of the agricultural revolution in sub-Saharan Africa is incomplete. Experts from multiple academic disciplines continue to debate the Bantu migration routes based on their evidence. Some even question whether they migrated at all.

One question to ask is why Bantu farmers moved from their homeland while their foraging ancestors did not. Leonard Ngcongco of the University of Botswana has explained 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 between 5000 and 2000 BCE. By about 1000 CE, farming replaced foraging as far away as the Swahili coast in eastern Africa.

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.