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 Somaliland. Zanzibar was famous worldwide for its spices and its slaves. During the 19th century, Zanzibar was known all over the world in the words of Petterson as: "A fabled land of spices, a vile center of slavery, a place of origins of expeditions into the vast, mysterious continent, the island was all these things during its heyday in the last half of the 19th century. It was the Africa Great Lakes' main slave-trading port, and in the 19th century as many as 50,000 slaves were passing through the slave markets of Zanzibar each year. (David Livingstone estimated that 80,000