Chad was inhabited as early as 3.5 million years ago by humanlike creatures known as australopithecines. The first human habitation dates from 5000 B.C. Various peoples, mainly from the north and east, migrated into the region, which became divided into many small kingdoms. About 800 A.D., the kingdom of Kanem arose northeast of Lake Chad. Crossed by major trans-Saharan trade routes, it became a flourishing trade center. Ouaddai and Baguirmi were other powerful kingdoms located in central and northern Chad. Slaves, taken during raids on the weaker Bantu groups of the south, were traded to North Africa.

The French first penetrated the region in the 1890's. Chad was made part of the French Congo, later called French Equatorial Africa. Chad gained internal autonomy in 1958 and became independent in 1960. The southern Bantus dominated the new government. Long-standing sectional conflicts erupted into rebellion by the peoples of the north in 1966.

Civil war intensified, and in 1978 the central government collapsed as various factions vied for control. Libya intervened on the side of one faction and occupied a third of the country. A faction led by Hissene Habre seized control in 1982 and gradually extended rule over most of Chad, except for the Aozou region, an area in the far north that Libya claimed and occupied. In 1990 Habre was overthrown by Idriss Deby, the leader of a rebel group called the Patriotic Salvation Movement (MPS). In 1994 Libya surrendered the Aozou region to Chad.

In 1996, presidential elections were held in Chad, and Deby won. That same year, a new constitution was adopted. The MPS won the most seats in Chad's legislative elections in 1997. Deby served another term as president after elections in 2001. Following legislative elections in 2002, the MPS remained in power.

In 1998, the Movement for Democracy and Justice in Chad (MDJC), based in northern Chad, started rioting against the government. In an effort to stop the fighting, the government and the rebels signed agreements in January, 2002, December, 2003, and August, 2005. Since 2003, about 200,000 Sudanese refugees have moved to eastern Chad because of conflict in the Darfur region of western Sudan.

In April, 2006, another group of rebels attacked the capital of N'Djamena. However, they were quickly defeated by government troops. In May, Deby was reelected president, but opposition parties boycotted the election. Then, in November, 2006, rebels rioted against government troops in some eastern cities.