Following the April 1964 union of newly independent Tanganyika and the island nation of Zanzibar after its own revolution, the merged state formally took the name United Republic of Tanzania on this date. Julius Nyerere, Tanganyika's president, became Tanzania's first president, pursuing a distinctive African socialist path known as Ujamaa that would define the country's politics for decades.
Zanzibar's 1964 revolution had overthrown the Sultan just weeks after Tanganyika's own independence, and the fragile new island government under Abeid Karume feared subversion from rival factions and outside powers amid Cold War anxieties over the presence of leftist organizers on the island. Union with the much larger mainland state of Tanganyika offered Zanzibar security and international legitimacy.
Julius Nyerere, already a respected pan-Africanist leader, negotiated the merger quickly, and after a few months of provisional arrangements, the two states adopted the permanent name United Republic of Tanzania on October 29, 1964, combining syllables from Tanganyika and Zanzibar.
The union preserved a distinct government for Zanzibar even within the new republic, a semi-autonomous arrangement that persists to this day and has occasionally strained relations between the mainland and the islands. Nyerere went on to implement Ujamaa, a program of collectivized agriculture and self-reliance that reshaped Tanzanian society, with mixed economic results but a lasting legacy of national unity and Swahili-language identity rare among African states with dozens of ethnic groups.