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 was characterized by fratricidal quarrels as it was common for brother to murder brother, and this was typical of the Arab aristocracy, where it was acceptable for family members to murder one another to gain land, wealth, titles and slaves. Visitors to Zanzibar often mentioned the "shocking brutality" which the Arab masters treated their African slaves, who were so cowed into submission that there was never a slave revolt attempted on Zanzibar. The cruelty which the Arab masters treated their black slaves left behind a legacy of hate, which exploded in the revolution of 1964. The Sultan of Zanzibar controlled