History of the Yoruba people military capital of Ilorin, and then sacked and destroyed Ọyọ-Ile, the royal seat of the Ọyọ Empire. Following this, Ọyọ-Ile was abandoned, and the Ọyọ retreated south to the present city of Oyo (formerly known as "Ago d'Oyo", or "Oyo Atiba") in a forested region where the cavalry of the Sokoto Caliphate was less effective. Further attempts by the Sokoto Caliphate to expand southwards were checked by the Yoruba who had rallied in defence under the military leadership of the ascendant Ibadan clan, which rose from the old Oyo Empire, and of the Ijebu city-states. However, the Oyo hegemony had
Oyo Empire balances on the power of the Alafin and the Oyo Mesi and thus no one is arrogated absolute power. The Ogboni was a very powerful secret society composed of freemen noted for their age, wisdom and importance in religious and political affairs. Its members enjoyed immense power over the common people due to their religious station. A testament to how widespread the institution was is the fact that there were Ogboni councils at nearly all sub-courts within Yorubaland. Aside from their duties in respect to the worship of the earth, they were responsible for judging any case dealing with the