In the early nineteenth century, Mayotta, the southernmost of the Comoro Islands situated at the northern end of the Mozambique Channel between the east African mainland and Madagascar, served as a depot for slaves exported from East Africa. From the 1820s, it also became a refuge for Sakalava from northwest Madagascar fleeing raids launched by the Merina of the high central plateau. Fear of the Merina caused the population of Mayotta to appeal for French protection in 1841 and in 1843 the island became a French colony. The French hoped that Mayotta would compensate them for the loss of Mauritius, seized by the British during the Napoleonic Wars and, unlike neighbouring Réunion island, not returned in the Peace settlement of 1814. The British retained Mauritius because it possessed in Port Louis a major port and dockyard, whereas Réunion possessed no good harbours. The French thus hoped that Mayotta, which had a good natural harbour, would give them an Indian Ocean naval base close to the major east African entrepôt of Zanzibar, where the Americans and British traders were dominant, and to Madagascar, to which the French had colonial claims.