The Roots of Black South Africa - David Hammond-Tooke

A revolution took place in southern Africa in the early centuries of the first millennium AD. Suddenly, in the warm lowveld and bushveld of what is now the Transvaal, there emerged settled communities, tilling the land, working metal, and creating a distinctive type of pottery. Before this time the country south of the Limpopo had been inhabited only by nomadic hunter-gatherers who used Late Stone Age tools. Slowly these newcomers the ancestors of todays black South Africans spread, with their herds of cattle, onto the savannah of the highveld and down into the coastal plains of the east.