In 1973, Libya engaged in military operations in the Aouzou Strip to gain access to minerals and to use it as a base of influence in Chadian politics. Libya argued that the territory was inhabited by indigenous people who owed allegiance to the Senussi Order and subsequently to the Ottoman Empire, and that this title had been inherited by Libya. It also supported its claim with an unratified 1935 treaty between France and Italy, the colonial powers of Chad and Libya, respectively. After consolidating its hold on the strip, Libya annexed it in 1976. Chadian forces were able to force the Libyans to retreat from the Aouzou Strip in 1987.