Nupe invasion and sack of Oyo Ile under Alafin Onigbogi

Under Alafin Onigbogi, son and successor of Oluaso, the Nupe invaded the Oyo kingdom and destroyed the capital at Oyo Ile. Onigbogi fled into exile in Borgu and the city of Oyo Ile was deserted; the Oyo kingdom ceased to exist as an effective political unit. Law dates this event to c. 1500 on revised genealogical grounds, though earlier scholars placed it c. 1535 or c. 1550. The collapse opened northern Yorubaland to Nupe and later Bariba raiding and settlement.