Northern Tanganyika's famed Olduvai Gorge has provided valuable demonstrate of the area's prehistory, including fossil remains of some of humanity's earliest ancestors. Discoveries suggest that East Africa may have been the site of human origin. Little is known of the history of Tanganyika's interior during the early centuries of the Christian era. The area is believed to have been colonised originally by ethnic groups using a click-tongue language similar to that of Southern Africa's Bushmen and Hottentots. Although remnants of these early tribes still exist, most were gradually displaced by Bantu farmers migrating from the west and south and by Nilotes and related northern peoples. Some of these groups had well-organized societies and controlled considerable areas by the time the Arab slavers, European explorers, and missionaries penetrated the interior in the first half of the 19th century.

President Nyerere stepped down from office and was succeeded as President by Ali Hassan Mwinyi in 1985. Nyerere retained his position as Chairman of the ruling party for 5 more years and was influential in Tanzanian politics until his death in October 1999. The current President, Benjamin Mkapa, was elected in 1995 and re-elected for a second five-year term in 2000. Zanzibar President Amani Abeid Karume, the son of Zanzibar’s first president, was elected in 2000, in general elections that were marked by widespread irregularities throughtout the Isles. His predecessor, Salmin Amour, was first elected in single-party elections in 1990, then re-elected in 1995 in Zanzibar’s first multi-party elections. These elections, also were tainted by widespread irregularities on Zanzibar.