From around the middle of the second millennium, there is little good archaeological evidence that can be accurately dated. However, sources for the events of this period in Zambia's history are the oral histories of Zambia's people, as well as their current languages and social traditions. The similarities and differences between the modern Zambian languages can be extrapolated by linguistic experts to point to the existence of about nine different root languages, which probably existed in Zambia in the 15th century AD.

The latter half of the second millennium ad saw the first chiefs, and hence kingdoms, emerge from Zambia's dispersed clans. The title 'chief' can be applied to anyone from a village headman to a god-like king. However, this was an era of increasing trade, when the groups with the largest resources and armies dominated local disputes. Thus it made sense for various clans to group together into tribes, under the rule of a single individual, or chief.

One of the oldest groups is thought to have been that of the Chewa people, led by the Undi, who came to the Luangwa area from the southern side of Lake Malawi in the 16th century. By the end of that century the Ng'andu clan (clan of the crocodile) established a kingdom amongst the Bemba people. These lived mostly in woodland areas, practising simple slash-and-burn types of agriculture. Perhaps because of the poverty of their lifestyle, they later earned a reputation as warriors for their raids on neighbouring tribes.

In the latter part of the 17th century the first recorded Lozi king (or Litunga, as he is known) is thought to have settled near Kalabo, in the west of Zambia, starting a powerful dynasty which lasts to the present day. Early in the 18th century Mwata Kazemba established a kingdom around the southern end of Lake Mweru in the Luapula Valley.