African trading empire ruled by the Sef (Sayf) dynasty that controlled the area around Lake Chad from the 9th to the 19th century. Its territory at various times included what is now southern Chad, northern Cameroon, northeastern Nigeria, eastern Niger, and southern Libya. Kanem-Bornu was probably founded around the mid-9th century, and its first capital was at Njimi. Toward the end of the 11th century, Kanem-Bornu became an Islamic state. Because of its location, it served as a point of contact in trade between North Africa, the Nile Valley, and the sub-Sahara region.