After World War II Britain gradually allowed the local people of Zanzibar to become involved in the island's government. Several local political parties were formed and Zanzibar's first elections were held in July 1957. The Afro-Shirazi union (which later became the Afro-Shirazi party – asp) defeated the Zanzibar nationalist party (ZNP). Broadly speaking, the asp was dominated by Africans, the ZNP by Arabs.

In October 1960 Sultan Khalifa died, after ruling for 49 years, and was succeeded by his only son, Abdullah. In November the same year Zanzibar was granted a new constitution which allowed for the elections of the members of the Legislative Council. Elections took place in January 1961, producing no clear result, and again in June 1961, but these were marked by serious inter-racial rioting. Nevertheless the ZNP, along with the aligned Zanzibar and Pemba People's Party, won 13 of the seats on the council, while the ASP won ten.

Britain realised that internal self-government for Zanzibar was inevitable, and this was finally granted in June 1963. In July that year Sultan Abdullah died. Throughout his short reign he had suffered from severe pains in his legs, which were eventually amputated. Abdullah was succeeded by his eldest son Jamshid.

On 10 December 1963 Zanzibar became an independent sultanate, and the coastal strip was finally ceded to Kenya, which became independent two days later. Zanzibar was made a full member of the British Commonwealth and on 16 December became a member of the United Nations. But the new sultanate was short-lived: on 12 January 1964 the Zanzibari government was overthrown in a violent revolution.