The Portuguese and the Omanis

Portuguese ships first reached the East African coast in 1498, on Vasco da Gama's voyage to India. They came back armed. In July 1502 da Gama anchored his fleet off Kilwa, the richest town on the coast, and threatened to bombard it; its ruler, Emir Ibrahim, agreed to pay a yearly tribute in gold, and da Gama declared Kilwa a vassal of Portugal. In 1503 another Portuguese captain forced Zanzibar to pay tribute too.

Kilwa soon stopped paying. In July 1505 a fleet under Francisco de Almeida stormed and sacked the town and built a fort there. The Portuguese abandoned it around 1512, but Kilwa's trade never recovered; how the city looked at its height is described on The Swahili coast and the Kilwa guide.

Portugal wanted the ocean's trade, not the land. It held the coast with warships, a few forts and the threat of attack, and took tribute from towns that kept their own rulers. Its stronghold was Fort Jesus at Mombasa, in present-day Kenya, built in 1593.

On Zanzibar the Portuguese presence was light; it left little beyond a chapel whose foundations now lie under the Old Fort in Stone Town.

The Omanis expelled the Portuguese from Muscat in the middle of the seventeenth century and then turned south. In 1696 an Omani fleet besieged Fort Jesus. It fell after 33 months, in 1698, and with it Portugal lost everything on the coast north of the Ruvuma, the river that is still Tanzania's border with Mozambique.

The Omanis built in their turn: the Old Fort on the Stone Town waterfront, around 1700, on the site of the Portuguese chapel, and Gereza on Kilwa Kisiwani, on the ruins of the Portuguese fort.

Through the eighteenth century Omani families settled on Zanzibar in growing numbers. In Oman itself the Busaidi dynasty took power around 1744; on the coast its main rivals were the Mazrui, the family that governed Mombasa and resisted Busaidi rule.

The trade in people grew. In 1776 the sultan of Kilwa signed a treaty with a French slave trader, Jean-Vincent Morice, to supply him with 1,000 enslaved people a year for French plantations on Mauritius and Réunion. Within a decade, in the 1780s, the Omanis took Kilwa too.

The Busaidi ruler Said bin Sultan spent more and more of his time on Zanzibar, where cloves were making the island rich, and in 1840 he moved his capital there from Muscat. That story, and the sultanate that followed, is told on Zanzibar: sultanate to revolution; what the Omani traders' caravans did inland is on The 1800s inland.