In the 7th millennium BC, ecological conditions in the northern half of Chadian territory favored human settlement, and the region experienced a strong population increase. Some of the most important African archaeological sites are found in Chad, mainly in the Borkou-Ennedi-Tibesti Region; some date to earlier than 2000 BC.
For more than 2000 years, the Chadian Basin has been inhabited by agricultural and sedentary peoples. The region became a crossroads of civilizations. The earliest of these were the legendary Sao, known from artifacts and oral histories. The Sao fell to the Kanem Empire, the first and longest-lasting of the empires that developed in Chad's Sahelian strip by the end of the 1st millennium AD. The power of Kanem and its successors was based on control of the trans-Saharan trade routes that passed through the region. These states, at least tacitly Muslim, never extended their control to the southern grasslands except to raid for slaves.
French colonial expansion led to the creation of the Territoire Militaire des Pays et Protectorats du Tchad in 1900. By 1920, France had secured full control of the colony and incorporated it as part of French Equatorial Africa. French rule in Chad was characterised by an absence of policies to unify the territory and sluggish modernisation. The French primarily viewed the colony as an unimportant source of untrained labour and raw cotton; France introduced large-scale cotton production in 1929. The colonial administration in Chad was critically understaffed and had to rely on the dregs of the French civil service. Only the south was governed effectively; French presence in the north and east was nominal. The educational system suffered from this neglect.
After World War II, France granted Chad the status of overseas territory and its inhabitants the right to elect representatives to the French National Assembly and a Chadian assembly. The largest political party was the Chadian
