Following independence movements in both territories, Tanganyika's President Julius Nyerere and Zanzibar's President Abeid Karume signed an agreement merging their nations into the United Republic of Tanzania. The union created one of Africa's most stable post-colonial states, blending mainland governance with Zanzibar's distinct Swahili and Arab-influenced culture.
Tanganyika had gained independence from Britain in 1961, and Zanzibar, an archipelago with a long history as an Arab sultanate and trading hub, achieved its own independence in December 1963, only to be upended weeks later by a revolution that overthrew its sultan. Amid regional Cold War anxieties about instability in Zanzibar, Nyerere and Karume moved quickly to formalize a union.
The merger, signed on April 22 and ratified by both legislatures with the formal proclamation on April 26, created a new name, Tanzania, a portmanteau of Tanganyika and Zanzibar, and a hybrid government granting Zanzibar significant autonomy over its internal affairs. Nyerere became president of the united republic, pursuing his socialist-inflected vision of African unity and self-reliance, known as Ujamaa.
The union has endured for six decades, remarkable in a region where many post-colonial mergers and borders fractured violently. Tensions between mainland and island politics persist to this day, with periodic debates over autonomy, but Tanzania has largely avoided the civil wars that plagued many of its neighbors, making the 1964 union one of Africa's rare lasting political experiments.