ABSTRACT
While slavery and the slave trade hold a time-deep history in eastern Africa – spanning more than 2,000 years (Beachey 1976: 3) – plantation slavery did not coalesce as a regional economic system until the nineteenth century. Then, prior economic dependence on the export of captives gave way to a system in which more slave labour was retained for the production of export crops, including cloves in Zanzibar and oil-producing grains on the Kenyan coast (Kiriama 2009: 107). This localisation of the slave economy was engendered in large part by British abolitionist efforts. Under British pressure, Omani colonialists ratified treaties that prohibited the sale of slaves to Europeans, allowed the British Royal Navy to arrest all slaving vessels in the waters of the western Indian Ocean, and prohibited exportation and importation of enslaved captives along the eastern African coast. While the export slave trade withered under such restrictions, the system of plantation slave labour that replaced it proved more enduring. In 1897, the Sultan of Zanzibar issued a decree abolishing slavery on the islands of Zanzibar and Pemba; this proclamation was followed in 1907 by a British colonial ordinance affecting the mainland Kenyan coast. Slavery would not legally end for residents of German East Africa (later mainland Tanzania) until 1922, shortly after the region was ceded to British control.
