... and the birth of the spice trade
In 1804 Sultan bin Ahmed of Oman was killed in battle, and his sons Salim and Said (aged 15 and 13) jointly inherited his kingdom with their cousin Bedr acting as regent. Two years later the young Said killed Bedr, who he believed was plotting to kill him; in 1806 he was proclaimed Sultan of Oman and the east African coast.
Said ruled his kingdom from Muscat and did not visit his African territories for several years. He maintained good relations with Britain because, like his father, he hoped for British help against the Persians and the Mazruis. During this period, wars and drought had drained Oman's economy, and many Omani merchants migrated to Zanzibar to participate in coastal trading and the caravans to the interior.
Meanwhile, in Europe, a campaign led by William Wilberforce resulted in the abolition of the slave trade within the British Empire in 1807. The USA passed a law against slave trading in 1808; the French and Germans did the same a few years later.
In east Africa, however, about 8,000 slaves were brought from the mainland to Zanzibar every year, many of them carrying ivory. The resultant surplus of slaves was addressed in 1812, when a Muscat-born Arab called Saleh bin Haramil al Abray introduced clove trees into Zanzibar from the island of Bourbon (now Réunion). The slaves were diverted to work on clove plantations and demand increased once again.
As the demand for slaves and ivory continued to expand, Arab traders from the coast pushed further inland. In 1820, they established a trading centre at Kazeh (near present-day Tabora, in Tanzania), over 800km (500 miles) from the coast. From Kazeh, trade routes branched north to the shores of present-day Lake Victoria, northwest to Buganda (now Uganda), and southwest to the southern end of Lake Tanganyika. (See Zanzibar and the slave trade map, opposite.)