The next people to arrive in Botswana were the Bantu-speakers. This collective term refers to a number of different tribes, from a related linguistic group, who gradually migrated down into southern Africa, from north of the Equator, over the course of thousands of years. The date of their arrival in Botswana is hard to pinpoint.
The Bantu were grain farmers (agriculturalists) as opposed to pastoralists or hunter-gatherers and they brought Iron Age technology with them; that is their tools and weapons were made of iron. Physically these Iron Age farmers were much taller and heavier than the Khoisan, and they became the ancestors of the modern black Africans in southern Africa.
Crucial to the production of iron is a smelting furnace capable of reaching very high temperatures. Associated with the Iron Age is a new kind of pottery, which also had to be fired at high temperatures. Archaeologists use the finds of pottery and iron to date the arrival of the new people on the landscape of Botswana.
It is thought that the Bantu-speakers arrived in two main waves, bringing western and eastern Bantu languages. From West Africa, Late Stone Age farmers on the upper Zambezi were converted to the use of iron tools by about 300BC. From East Africa, Early Iron Age farming spread south along the east coast as far as the Zambezi by around 20BC.
By 200BC, in the Okavango-Makgadikgadi region, people were making a kind of pottery which archaeologists think was Khoe pottery influenced by western Iron Age (Bantu) styles, suggesting an initial contact between the two groups. The major Bantu influx probably occurred around the first few centuries AD, and the ancestors of the Khoisan people, with their simple Stone Age technology and hunter-gatherer existence, just could not compete. Since then the Khoisan have gradually been either assimilated into the migrant groups, or effectively pushed into the areas which could not be farmed. Thus the older Stone Age cultures persisted for much longer in the Kalahari (which is more difficult to cultivate) than in the rest of the country.
In theory, the stronger iron weapons of the Bantu should easily have made them the dominant culture. However, it took a very long time for Bantu language and culture to replace that of the Khoe – as late as the 19th century people were still speaking Khoe on the Boteti River. This supports a theory of communities living peacefully there, side by side, for a thousand years or more.
There is some evidence of inter-marriage or inter-breeding between the two groups and the Batswana today are a mixture of Bantu and Khoisan features and they are noticeably lighter in skin colour than Bantu-speakers further north. They also tend to have the almond eyes, high cheekbones and thin lips of the Khoisan.