The rise of the Kanem-Borno Empire in the 9th century was primarily due to

Kanem-Borno controlled key trans-Saharan trade routes in the 9th century. Merchants traded salt, gold, slaves, and other goods across the desert. This trade brought enormous wealth and power to the empire.

Military conquest happened but wasn’t the primary cause of their rise. Agriculture supported the population but trade created wealth. The Ottoman Empire was too far away for diplomatic alliances at that time.

Trade routes were like highways of wealth in medieval Africa. Whoever controlled them became rich and powerful.