Former African empire around Lake Chad .
It was ruled by the Sef dynasty in the 9th19th century. Its territory at various times included what is now southern Chad, northern Cameroon, northeastern Nigeria, eastern Niger, and southern Libya. Probably founded in the mid-9th century, it became an Islamic state at the end of the 11th century. Its location made it a trading hub between North Africa, the Nile Valley, and the sub-Saharan region. From the 16th century Kanem-Bornu, sometimes called simply Bornu, was extended and consolidated. The Sef dynasty died out in 1846.