Political map of Northern Africa 14 March 1913 (French invasion of the Tibesti): The Anglo–French Treaty of 1899 (Anglo-French Convention of 1898) placed the Tibesti Mountains (in the central Sahara) within French borders. This claim was disputed by the Ottoman Empire, but when the Ottomans were defeated by Italy in Tripolitania in 1911–12, they were compelled to abandon the region. The French took the opportunity to invade the Tibesti the following year (French invasion of the Tibesti), where they now faced and defeated the Senussi, but were in turn forced to withdraw during the desert revolts of World War I. It would not be until 1929–30 that the French would finally pacify the region.