Kanem-Bornu Empire
Islamization began as early as the 8th century and was mostly complete by the 11th, when Islam became the official religion of the Kanem-Bornu Empire. The Shuwa established an economy of slave trade across the Sudan region, and in Chad there was a tradition of slave raids (ghazw) under the Ouaddai and Baguirmi which persisted well into the 20th century.