Italy meanwhile, which desired territory in the area of modern Libya, sought to emulate the colonial expansion of the other European powers, and they indicated their recognition of the above line to France on 1 November 1902.[5] The Ottoman Empire had ruled the coastal areas of what is today Libya since the 16th century, organised into the Vilayet of Tripolitania, with an ill-defined border in the south.[5] In September 1911 Italy invaded Tripolitania, and the Treaty of Ouchy was signed the following year by which the Ottomans formally ceded sovereignty of the area over to Italy.[6][7] The Italians organised the newly conquered region into the colonies of Italian Cyrenaica and Italian Tripolitania, and gradually began pushing the limits of the territories to the south; later, in 1934, they united the two territories as Italian Libya.[8] France and Italy delimited the border between French Algeria and Italian Libya in 1919, which also covered the segment of the modern Libya–Niger border as far south as Tumu.[5] The precise details of the delimitation of the section east from Tumu to the Chad tripoint remains somewhat hazy, however the convention line as currently in place appears to have been agreed upon at some time in this period.[6] The Libya-Niger was formerly longer than it is currently, prior to the transfer on 18 March 1931 of the Tibesti Mountains from Niger to Chad.