Flag of Zanzibar yellow cloves was added to the flag. On 12 January 1964, John Okello overthrew the Sultan of Zanzibar and adopted a black-yellow-blue tricolour as the flag of the People's Republic of Zanzibar and Pemba. On 29 January, the country's flag was changed to a blue-black-green tricolour with a thin white stripe at the hoist. This design, which was based on the flag of the Afro-Shirazi Party, was the longest-lived of the post-independence flags and eventually formed the basis for the current flag. On 26 April 1964, Zanzibar united with Tanganyika to form the new country of Tanzania and Zanzibar's old
History of Zanzibar place to this day. The third pillar of the economy was slaves, which gave Zanzibar an important place in the Arab slave trade, the Indian Ocean equivalent of the better-known Triangular Trade. The Omani Sultan of Zanzibar controlled a substantial portion of the African Great Lakes coast, known as Zanj, as well as extensive inland trading routes. Sometimes gradually, sometimes by fits and starts, control of Zanzibar came into the hands of the British Empire. In 1890, Zanzibar became a British protectorate. The death of one sultan and the succession of another of whom the British did not approve later