The spice islands off the East African coast that became, in the nineteenth century, the seat of an Omani Arab sultanate and the commercial heart of the East African and Indian Ocean trade in cloves, ivory, and enslaved people — a small archipelago where the wealth of plantation agriculture and the suffering of a slave system dominated by Omani-Arab elites, financed through Indian Ocean commercial networks and worked by enslaved Africans, were bound tightly together — the older Swahili trading world reorganized under an Omani-Zanzibari commercial empire.
In 1840 a ruler of Oman did something almost no monarch has done. He moved his capital from Arabia to Africa. Sultan Said bin Sultan shifted his court from Muscat across the ocean to Zanzibar, a small island off the East African coast. He came for cloves and for trade. Within a generation the island had become the busiest slave market on the eastern side of Africa, and one of the world's leading producers of a spice. The same island held both stories at once, and it has been trying to hold them ever since.