The Unguja Island (Zanzibar) became an important stronghold of
the Sultanate of Muscat and Oman. In 1840, sultan Seyyid Said
moved the capital from Muscat to Zanzibar, and after his death in
1856, the state was divided: Unguja and its tributary territories in East
Africa formed Zanzibar Sultanate under the authority of one branch of
Seyyid Said's descendants and Omani Sultanate was under the reign
of another branch. Zanzibar Sultanate continued to exist under the
British protectorate from 1890 before it gained independence in 1963.
During the 1964 revolution suntan was dethroned, and Zanzibar be-
came a part of united Tanzania the same year.
Historically, the Omani dynasty of Zanzibar, its elite, and Arab
traders turned out deeply involved in the slave trade and slave-
holding, and became the main force in the region in this regard. The
slave trade itself began to expand initially due to the development of
European colonial plantation economy. In the 18th Century, the French
founded sugar cane plantations in Mauritius (Île-de-France) and Reun-
ion (Bourbon), which needed much more manpower than the local
population could provide. This boosted a demand for slaves: the ma-
jority came from Mozambique, and about a quarter was provided by
Kilwa (see Gerbeau 1979; Ogot 1979: 177; Klein 2005: 1384). The
British who seized Mauritius, in 1821 restricted the importation of
slaves to the island, and the following year a treaty with the sultan of
Muscat (Moresby Treaty) prohibited the Omanis to bring slaves to
British possessions in India and the Indian Ocean, as well as selling
slaves to Christians of any nationality. But Bourbon, still belonging to
the French, continued to receive labor force from the ports of East Af-
rica – Zanzibar, Mombasa, Takaungu and Lamu (Ogot 1979: 177).
In the first half of the 19th Century, extensive plantations of cloves,
coconuts and grains were established on Zanzibar and Pemba and thus
they required even more labor than the plantations of Mascarene Is-
lands. Their owners were the Hadhramaut and Omani Arabs, as well
as local Swahili businesspersons from the continent. During the reign
of Seyyid Said, the island became the world's leading supplier of
cloves and the largest slave market in East Africa (Collins 2006: 339).
In addition to meeting the needs of Zanzibar and Pemba, slaves
were taken to Arabia, the countries of the Persian Gulf, India, the is-
lands of Reunion, Mauritius, Madagascar, the Comoros and Sey-
chelles (Gerbeau 1979: 199; Ogot 1979: 177–178; Austen 1988: 21