France proclaimed a protectorate over Chad in 1900 and in July 1908 the territory was incorporated into French Equatorial Africa. It became a separate colony in 1920, and in 1946 one of the four constituent territories of French Equatorial Africa. It achieved full independence on 11 Aug. 1960. Conflicts between the government and secessionist groups, particularly in the Muslim north and centre, from 1965 led to civil war. In 1982 Hissène Habré gained control of the country. In June 1983 Libyan-backed forces reoccupied some territory but a ceasefire took effect in Sept. 1987. Rebel forces of the Popular Salvation Movement led by Idriss Déby entered Chad from Sudan in Nov. 1990. On 4 Dec. 1990 Déby declared himself president.