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. French rule in Chad was characterized by an absence of policies to unify the territory and sluggish modernization. The French primarily viewed the colony as an unimportant source of untrained labor 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 Progressive Party (PPT), based in the southern half of the colony. Chad was granted independence on August 11, 1960 with the PPT's leader, François Tombalbaye, as its first president.
Two years later, Tombalbaye banned opposition parties and established a one-party system. Tombalbaye's autocratic rule and insensitive mismanagement exacerbated interethnic tensions. In 1965 Muslims began a civil war. Tomalbaye was overthrown and killed in 1975, but the insurgency continued. In 1979 the rebel factions conquered the capital, and all central authority in the country collapsed. Armed factions, many from the north's rebellion, contended for power. The disintegration of Chad caused the collapse of France's position in the country. Libya moved to fill the power vacuum and became involved in Chad's civil war. Libya's adventure ended in a disaster in 1987; the French-supported president, Hissène Habré, evinced a united response from Chadians of a kind never seen before and forced the Libyan army off Chadian soil.
Habré consolidated his dictatorship through a power system that relied on corruption and violence; an estimated 40,000 people were killed under his rule.The president favoured his own Daza ethnic group and discriminated against his former allies, the Zaghawa. His general, Idriss Déby, overthrew him in 1990.
Deby attempted to reconcile the rebel groups and re-introduced multiparty politics. Chadians approved a new constitution by referendum, and in 1996, Déby easily won a competitive presidential election. He won a second term five years later. Oil exploitation began in Chad in 2003, bringing with it hopes that Chad would at last have some chances of peace and prosperity. Instead, internal dissent worsened, and a new civil war broke out. Déby unilaterally modified the constitution to remove the two-term limit on the presidency; this caused an uproar among the civil society and opposition parties. In 2006 Déby won a third mandate in elections that the opposition boycotted. Ethnic violence in eastern Chad has increased; the United Nations High Commissioner for Refugees has warned that a genocide like that in Darfur may yet occur in Chad.