Early migrations into East Africa
Cushitic peoples
Historical linguistic research has suggested that ancestral southern Cushitic peoples moved into the Turkana area from the north in Ethiopia around 5000 years ago. Fish remains have been found at early sites. Cushitic traditions abhors consumption of fish so by these findings, fish prohibition is a more recent phenomenon.
The earliest livestock bones in East Africa were recovered at Dongodien, in the Koobi Fora area on the east side of Lake Turkana. Radiocarbon dating suggests an age of approximately four thousand years ago. Both bones of cattle (mostly Bos Taurus, a humpless species. Bos Indicus, or Zebu, a humped, more common today in the North was introduced starting from AD 100, from the East African coast) and goats, or caprines (goat-like), were recovered. More evidence dated to approximately thirty-five hundred to four thousand years ago was also excavated at the Ileret Stone Bowl site on the northeast side of Lake Turkana.
By 4,000 years ago, the Southern Cushites had moved from the Ethiopian highlands and their descendants can be found mostly in Tanzania today.
The Eastern Cushitic group also migrating from the Ethiopian highlands and the horn of Africa dispersed throughout Northern Kenya and even to the Coast by the AD 1,000.
Nilotic peoples
Some Nilotic peoples migrating along the Nile valley from lower Egypt and Sudan moved out of Lake Turkana area between the 10th and 14th centuries AD. Nilotic speakers are further subdivided into highland, plain and river-lake Nilotes. The plain Nilotes had mostly settled on the Central and Southern Rift Valley by the 18th century. Other groups had reached the western Kenya lake basin by the 16th century.
Bantu peoples
Starting between 3,000 and 2,500 years ago, Bantu expanded southwards and eastward, first from the Cameroon highlands and later from Equatorial forests of Central Africa. Between 2,000 and 1,500 years ago they had began to exert their influence to the west of the Lake Victoria shores as evidenced by the Urewe and Early Iron Age industries.
The Bantu expansion is likely as a result of population increase because of successful subsistence agriculture and accelerated technological innovation.
Between 1,900 and 1,800 years ago the eastern bound Bantus had appeared in Southern Kenya and along the Tanzanian coast developing the Early Iron Age pottery tradition of the coastal zone known as the Kwale pottery industry.
The Bantus continued to move south, reaching the South African lowlands by 1,600 – 1,500 years ago.