Teso traditions relate that they originated somewhere in what is now Egypt in the area of Alexandra. They are believed to have descended from the Hebrew Joseph who had married a black Egyptian. Later when the Israeli slaves left Egypt for the promised land, the group followed the blue Nile river into Ethiopia. It is from here that they obtained the name Iteso, meaning we have seen. They saw a land, part of the promise to Jacob, the grand son of Abraham, it is a land divided by small rivers originating from the White Nile, theirs was the Upper Nile area. From the Ethiopian mountains is where they saw the land. They later migrated south West over a period of centuries. They were part of a larger group of Nilo-Hamitic peoples who include; the Masai and Turkana of Kenya, the Nyangatom of present day Ethiopia, Karamojong, the Topotha of South Sudan, all are they Ateker. The Ateker further split into several groups, including Jie, Turkana, Karamojong and Teso.
The Teso established themselves in present-day north-eastern Uganda, and in the mid-18th century some began to move farther south. During the course of this latter migration, conflicts ensued with other ethnic groups in the region, leading to the split of Teso territory into a northern and southern part. In 1902, part of eastern Uganda was transferred to western Kenya – leading to further separation of Teso.
Northern Teso occupy the area previously known as Teso District in Uganda (now the districts of Amuria, Soroti, Kumi, Katakwi, Pallisa, Bukedea and Kaberamaido). Southern Teso live mainly in the districts of Tororo and Busia in Uganda, and Busia District in Kenya’s Western Province.
The Teso in Kenya, numbering about 279,000, live mainly in Busia District, Teso District.
KSM is located in North Teso near Malaba which borders Uganda. The Teso People are known to be the best in the field of witchcraft and people would come from all over to be taught the rituals. At present, there is a King of Teso and he resides in Uganda. He comes to visit the Teso People in Kenya once a year.