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
History of the Yoruba people been dealt a mortal blow. The other Yoruba city-states broke free of Oyo dominance, and subsequently became embroiled in a series of internecine conflicts that soon metamorphosed into a full scale civil war. These events weakened the southern Yorubas in their resistance to British colonial and military invasions. In 1960, greater Yorubaland was subsumed into the Federal Republic of Nigeria. The historical records of the Yoruba, which became more accessible in the nineteenth century with the more permanent arrival of the Europeans, tell of heavy Jihad raids by the mounted Fulani warriors of the north as well as of endemic