The first pottery in South Africa associated with the Sotho-Tswana is called Icon and dates to between 1300 and 1500. As with the Nguni, anthropological and linguistic data suggest an East African origin for Sotho-Tswana speakers, though in this case in what is now Tanzania. The earliest Sotho-Tswana were concentrated in the northern part of South Africa. By 1500 they had expanded to the south and west and separated into three distinct clusters, defined in terms of ceramic style.
There is a close correspondence between these ceramic style clusters and separate branches of the Sotho-Tswana. Thus, the Western Sotho-Tswana cluster, north of the Waterberg and west to the Limpopo, is associated with the Hurutshe and Kwena branch, while the Southwestern cluster, in the Magaliesberg and south to the Vaal, is linked to the Rolong and Tlhaping branch. A Northwestern cluster occurs in Botswana and northwest South Africa, but its more recent history is currently unknown. The Southern Sotho-Tswana cluster, associated with the Fokeng, has an Nguni origin. Since each Sotho-Tswana branch claims a separate origin, represented by these ceramic clusters, the Icon phase of Sotho-Tswana settlement in South Africa is beyond oral tradition.
Fokeng communities expanded north, west and southwards from the Ntsuanatsatsi area. They reached the edges of the Caledon valley in the 1600s, where the Phetla had already settled. North of the Vaal they made contact with Southwestern and then Western Sotho-Tswana folk. In the Waterberg in the 1600s, conflict over limited resources seems to have provoked discord, in this case between Nguni speakers and mixed groups of Fokeng and Western Sotho-Tswana people. Sometime before 1700, some Western Sotho-Tswana people, including Kwena communities, moved south across the Vaal, into the Fokeng area. As a result of this contact and acculturation, the Fokeng became Sotho and, in the Free State, all but vanished. In turn, Western and Southwestern groups in the 1700s adopted building in stone from the Fokeng. People of each cluster built distinctive stonewalled settlements, which presumably reflected the details of their earlier settlements of wood and thatch. The variously organised settlements, like ceramics, allow archaeologists to trace movement and interaction across the landscape. What is clear is that pulses of settlement shifts and conflict seem to have been at least partly a response to climatic flux during the Little Ice Age. For instance, an improved climate after 1700 made it possible for Southwestern Sotho-Tswana to settle south of the Vaal River, on the western edges of Fokeng-Kwena territory.
From 1750 onwards, intensifying trade and more intrusive colonial expansion increasingly affected Sotho-Tswana societies. Competition and conflict for resources eventually forced some chiefdoms to ‘implode’ into huge defensive settlements such as Molokwane, Kaditshwene and Dithakong, which in the early 1800s housed 10 000 people or more.
