Sao

The Sao built fortified city-states by Lake Chad and the Chari River. Their cities flourished between the ninth and fifteenth centuries.

Around 1500 the Kotoko inherited the Sao city-states and founded a kingdom. In the sixteenth century Bornu expanded and Islam changed Sao society. Bornu merchants and clerics spread Islam among the Kotoko; some communities converted only in the eighteenth century.