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
Yoruba people the monarchy was open to the election of any free-born male citizen. In Ilesa, Ondo, Akure and other Yoruba communities, there were several, but comparatively rare, traditions of female "Ọbas". The kings were traditionally almost always polygamous and often married royal family members from other domains, thereby creating useful alliances with other rulers. Ibadan, a city-state and proto-empire founded in the 18th century by a polyglot group of refugees, soldiers, and itinerant traders from Ọyọ and the other Yoruba sub-groups largely dispensed with the concept of monarchism, preferring to elect both military and civil councils from a pool of eminent