The Kotoko kingdom was a monarchy in what is today northern Cameroon and Nigeria, and southwestern Chad.
Kotoko spread to parts of what is today northern Cameroon and Nigeria, and southwestern Chad by the mid-15th century.
That same century, Kotoko itself was completely subsumed into the Bornu Empire, and Islam continued to spread.
The Bornu rulers divided the territory into northern and southern halves, which allowed Logone-Birni in the south to maintain some degree of autonomy under its paramount chief.
Kotoko, along with the rest of Bornu, was split among European powers during Africa's colonial period.