The Turkana are the largest of the seven ethnic groups that make up what is called the 'Karamajong cluster', which includes the Karamajong, Jie, Teso, Dodos and Donyiro in Uganda, and the Toposa of Sudan. The actual name "Turkana" is something of a mystery, with the most commonly ascribed meaning being a corruption of 'turkwen', which means 'cave people', or 'aturkan' which means 'cave land'.
As there are no caves in present-day Turkana-land (at least east of the Ugandan border), they must have migrated from elsewhere. This much is certain, as each of the nineteen sections of the Turkana agree that their recent origins lie to the west of their current homeland. The story, which has been carried down from mouth to mouth for many centuries, goes something like this:
A long time ago, the common ancestors of the Turkana, the Jie and all the other 'Karamajong' tribes, lived in a place called Apuli, which was in southern Sudan or Ethiopia. Some 300 to 500 years ago, they began to migrate southwards to their present homeland in the far northeast of Uganda.
After a while, a group of young men from the Jie section of the Karamajong were sent eastwards into the Tarach Valley (west/northwest of Lodwar in Kenya) in search of a wayward ox, whose tracks they were following. They wandered far from their people, and finally met a solitary old Jie woman called Nayece who was gathering fruit. She led the young warriors into a lush and and verdant valley, unoccupied by people, which was rich in the wild berries which still form an important part of the Turkana diet.
Nayece also gave the men fire, and taught them how to cook. Impressed with the area, the men talked other young people into joining them, and together they moved in with their livestock. Nayece divided the men into territorial sections (the basis of Turkana society today), and became the mother-heroine of the Turkana. Ever since, the Turkana and Jie have been allies.
Historically, this story is not disputed: the Turkana, as well as most historians, accept that the Turkana broke with the Jie around the middle of the eighteenth-century, probably during extreme drought, and migrated eastwards over the Dodoth Escarpment in northeastern Uganda and into Kenya following the Tarach (or Tarac) river.
Their "cave land" (aturkan) may well have been a hill called Moru a Nayece. The migrations may also have been caused by livestock overcrowding, brought about by successive migrations from the north, which - if the present climate is anything to go by - would have led to protracted feuding and fighting between the various Karamajong groups. Once in Kenya, the seasonal Turkwel and Kagwalasi (or Nakwehe) river valleys would have aided rapid dispersal into present-day Turkana District.
It is generally accepted that at least two separate migrations into Kenya took place, most probably in the form of successive sweeps, as there's also an oral history which states that, some two to three hundred years ago, the Turkana started to move southward towards the Kagwalassi and Turkwel Rivers which flow into Lake Turkana, where the episode with the wayward ox in the Tarach Valley occured.
The Turkana themselves make a distinction between an agriculturalist section named Ngicuro (who live in the western highlands on the Ugandan border), who are said to have come from the Teso people; and the remaining eighteen pastoralist sections called Ngimonia, who came from the Jie.
What is important to note is that the Turkana are indisputably related to the Karamajong tribes (and keep a number of their traditions to the present-day, such as not circumcising), and that they came originally from the north in what is now Southern Sudan or Ethiopia.
This southward-moving pattern is familiar throughout Kenya, not just among Nilotic and Cushitic tribes, but also among the Bantu of central Kenya and the Mijikenda of the coast. This would seem to reflect the increasing aridity of the northern tropics, which is the same mechanism by which the Sahara expanded and still continues to expand, pushing its original inhabitants outwards like foam on the edge of a wave.