Cave paintings indicate that Chad was a fertile and populous country in ancient times. By the 9th century ad, the kingdom of Kanem (see Kanem-Bornu Empire) was established in what is now western Chad, with its capital at Njimi, near Mao. Its rulers adopted Islam in the 11th century. Kanem was subjected to neighboring Bornu in the 16th century, and in the succeeding period the chief powers were the sultanates of Baguirmi and Wadai in the south. The export of slaves to North Africa was an important sector of the economy of these states.

The region of the eastern Sahara and Sudan from Fezzan, Bilma, and Chad in the west to the Nile valley in the east was well peopled in Neolithic times, as discovered sites attest. Probably typical of the earliest populations were the Negroid cave dwellers described by Herodotus as inhabiting the country south of Fezzan. The ethnographic history of the region is that of gradual modification of this basic stock by the continual infiltration of nomadic and increasingly Arabicized white African elements, entering from the north via Fezzan and Tibesti and, especially after the 14th century, from the Nile valley via Darfur. According to legend, the country around Lake Chad was originally occupied by the Negroid Sao. This vanished people is probably represented today by the Kotoko, in whose country, along the banks of the Logone and Chari, was unearthed in the 1950s a medieval culture notable for work in terra-cotta and bronze.

Tombalbaye’s successor, General Félix Malloum, was not able to end the civil strife. By 1979 the war had engulfed the south, Malloum was overthrown, and a northerner, Goukouni Oueddei, emerged as president. In 1980 Libya intervened to support Oueddei against rebels under former defense minister Hissène Habré, who was backed by Sudan and Egypt. After the Libyan forces withdrew late in 1981 at Oueddei’s request, Habré renewed his offensive, and his troops captured N’Djamena in June 1982. In 1983 the ousted Oueddei formed a rival government in the north. In the continued civil strife, Oueddei had the backing of Libyan troops, while France sent troops and supplies to keep Habré in power.