Portugal had occupied parts of the Mozambique coast since the 16th century, but at the start of the 19th century Portuguese presence was limited to Mozambique Island, Ibo and Quelimane in northern Mozambique, outposts at Sena and Tete in the Zambezi valley, Sofala to the south of the Zambezi, and the port town Inhambane even further south. Although Delagoa Bay was regarded as Portuguese territory, Lourenço Marques was not settled until 1781, and was temporarily abandoned after a 1796 French raid. In the late 18th century most of the people exported as slaves through Portuguese settlements in Mozambique were sent to Mauritius and Réunion, at that time both French colonies, but the Napoleonic Wars disrupted this trade, and by the early 19th century the Portuguese sent many enslaved people to Brazil. As was the case with Angola, exports of enslaved people declined after 1830 and were partly replaced by exports of ivory through Lourenço Marques from the 1840s onward.