Who ruled Zanzibar?

Zanzibar City faces west from Unguja, the largest island in its archipelago, across a 35-kilometre channel from mainland Tanzania. Its sheltered harbour lies in the path of the monsoon winds, which for centuries carried ships between East Africa, Arabia and India on a yearly cycle. That trade made the town a meeting place of African, Arab, Persian and Indian peoples, and in the 19th century the capital of a commercial empire built on cloves, ivory and enslaved people. Its old quarter, Stone Town, still shows that layered past.

Bantu-speaking farmers and fishers lived on Unguja by the first millennium CE, and the island became part of the coastal Swahili culture that grew from trade with the Muslim world. An inscription in the mosque at Kizimkazi, in the south of the island, dates its founding to 1107, one of the oldest such records on the coast. The island's towns were small, however, compared with mainland ports such as Kilwa and Mombasa.

Portuguese ships reached the coast after Vasco da Gama's voyage of 1498, and in about 1503 a Portuguese captain forced the ruler of Unguja to pay tribute. The island became a minor outpost of the Portuguese Empire for nearly two centuries. In 1698 Omani Arabs captured Mombasa from the Portuguese, and Zanzibar came under the authority of the sultans of Oman.

The town's great age began under Sayyid Said bin Sultan, ruler of Oman, who spent increasing time on the island and in 1840 made it his capital. Arab landowners planted cloves across Unguja and the neighbouring island of Pemba, worked by enslaved Africans, and the archipelago became the world's leading producer. Caravans financed by Indian merchants pushed deep into the African interior for ivory and captives, and Zanzibar became the largest slave market on the East African coast. Coral-stone mansions, mosques and carved wooden doors gave Stone Town its character. When Said died in 1856, his sons divided his realm, and from 1861 Zanzibar was a separate sultanate ruling the coast of what is now Kenya and Tanzania.

Britain used its growing influence to press for an end to the slave trade, and in 1873 Sultan Barghash closed the slave market; an Anglican cathedral was later built on its site. As the European Scramble for Africa carved up the mainland, the sultan's mainland coast was leased or sold to the British and the Germans, and in 1890 Zanzibar became a protectorate of the British Empire. When a claimant to the throne defied the British in August 1896, a naval bombardment of the palace forced his surrender in well under an hour, an episode often called the shortest war in history. Slavery itself was abolished in 1897.

Zanzibar became independent on 10 December 1963 as a constitutional monarchy under the sultan, but on 12 January 1964 a revolution overthrew the government. Thousands of Arabs and South Asians were killed and many more fled. On 26 April 1964 Zanzibar united with Tanganyika, forming the state that was soon renamed Tanzania, though the islands keep their own president and parliament.

Stone Town was listed by UNESCO in 2000. Zanzibar City, with several hundred thousand people in its wider urban area, is the seat of the semi-autonomous Zanzibar government and the main port of the islands.