<P> The Bantu expansion is a major series of migrations of the original proto - Bantu language speaking group, who spread from an original nucleus around West Africa - Central Africa across much of sub-Sahara Africa . In the process, the Proto - Bantu - speaking settlers displaced or absorbed pre-existing hunter - gatherer and pastoralist groups that they encountered . </P> <P> The primary evidence for this expansion is linguistic - the languages spoken across Sub-Equatorial Africa are remarkably similar to each other, suggesting the common cultural origin of their original speakers . The linguistic core of the Bantu languages, which comprise a branch of the Niger--Congo family, was located in the adjoining regions of Cameroon and Nigeria . However, attempts to trace the exact route of the expansion, to correlate it with archaeological evidence and genetic evidence, have not been conclusive; thus although the expansion is widely accepted as having taken place, many aspects of it remain in doubt or are highly contested . </P> <P> The expansion is believed to have taken place in at least two waves, between about 3,000 and 2,000 years ago (approximately 1,000 BCE to 1 CE). Linguistic analysis suggests that the expansion proceeded in two directions: the first went across the Congo forest region (towards East Africa), and the second - and possibly others - went south along the African coast into Gabon, the Democratic Republic of the Congo, and Angola, or inland along the many south - to - north flowing rivers of the Congo River system . The expansion reached South Africa, probably as early as 300 AD . </P> <P> Initially archaeologists believed that they could find archaeological similarities in the ancient cultures of the region that the Bantu - speakers were held to have traversed; while linguists, classifying the languages and creating a genealogical table of relationships believed they could reconstruct material culture elements . They believed that the expansion was caused by the development of agriculture, the making of ceramics, and the use of iron, which permitted new ecological zones to be exploited . In 1966 Roland Oliver published an article presenting these correlations as a reasonable hypothesis . </P>

What impact did the bantu have on sub-saharan africa