The African rulers of Zanzibar relied on slave labor just as white plantation owners of the American South did. During the 19th century, African slaves composed up to 90 percent of the island's population. Slaves worked on the island's clove plantations, where conditions were harsh and many slaves became ill and died. This fueled the demand for new slaves, driving a vigorous slave trade that brought Africans from East and Central Africa.

Growing British influence in the 1860s and 1870s led to the end of slavery in Zanzibar.

Picture: Bojan Brecelj/CORBIS