World historians are frequently occupied, sometimes almost exclusively, with civilizations, and understandably so, since those urban and state-based communities were clearly the most powerful, expansive, and innovative societies, later embracing almost the entire population of the planet. And yet, it is useful to remind ourselves that other ways of organizing human communities evolved alongside civilizations, and they too made history. Two such regions were Africa south of the equator and North America. They shared environments that featured plenty of land and relatively few people compared to the greater population densities and pressure on the land that characterized many civilizations.

In the vast region of Africa south of the equator, the most significant development during the second-wave era involved the accelerating movement of Bantu-speaking peoples into the enormous subcontinent. It was a process that had begun many centuries earlier, probably around 3000 B.C.E., from a homeland region in what are now southeastern Nigeria and the Cameroons. In the long run, that movement of peoples generated some 400 distinct but closely related languages, known collectively as Bantu. By the first century C.E., agricultural peoples speaking Bantu languages and now bearing an ironworking technology had largely occupied the forest regions of equatorial Africa, and at least a few of them had probably reached the East African coast. In the several centuries that followed, they established themselves quite rapidly in most of eastern and southern Africa (see Map 6.1), introducing immense economic and cultural changes to a huge region of the continent.

Bantu expansion was not a conquest or invasion such as that of Alexander the Great; nor was it a massive and self-conscious migration like that of Europeans to the Americas in more recent times. Rather, it was a slow movement of peoples, perhaps a few extended families at a time, but taken as a whole, it brought to Africa south of the equator a measure of cultural and linguistic commonality, marking it as a distinct region of the continent.