Summary

Eastern Africa was a source of enslaved African laborers for Indian Ocean markets for nearly two thousand years. However, it was only from the late 18th century that rising demand became closely linked to the industrializing economies of the Western world and their demand for tropical products. The slave trade in the 19th century consisted of two overlapping sectors. The first was a trade in enslaved Africans to markets along the Indian Ocean coast from northern Mozambique to southern Somalia, as well as export to destinations around the Indian Ocean. The plantations of the French Mascarene Islands were an early destination. From the first quarter of the 19th century, the main market for enslaved labor shifted to the clove plantations of the Omani Sultanate in Zanzibar and Pemba, as well as to coastal grain production. The second sector was an internal trade that provided labor for commercializing African societies and the infrastructure required for long-distance trade. For reasons related to the region’s geographical characteristics and disease environment, caravan transport by human porters was the only viable transport option to move ivory exports and cloth imports. Although in most regions east of Lake Tanganyika, caravan porterage was the work of Nyamwezi and Swahili waged laborers, enslaved labor increasingly characterized commercial agriculture, domestic work, and concubinage along the coast and in trade centers in the interior. Porterage west of Lake Tanganyika was largely the work of enslaved laborers. Slaving and the accumulation of enslaved individuals by commercially minded chiefs, warlords, farmers, and big traders followed the three main caravan routes as far as the Lake Victoria and Lake Tanganyika regions, the eastern Congo, and south-central Africa. As elsewhere in Africa, the trade rested on violence as labor demands increased. The long-distance trade system rapidly expanded due to the constant search for new sources of ivory and rising African consumption of imported products. Both sectors—the export of enslaved individuals and their accumulation at interior trading centers—were thus stimulated by the rapid integration of the region into the expanding capitalist global economy.