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 century. It is due to the influence of Bishop Samuel Ajayi Crowther, the first Anglican bishop in Nigeria. Crowther was himself an Oyo Yoruba and compiled the first Yoruba dictionary as well as introducing a standard for Yoruba orthography. The alternative name "Akú", apparently an exonym derived from the first words of Yoruba greetings (such as "Ẹ kú àárọ?" "good morning", "Ẹ kú alẹ?" "good evening") has survived in certain parts of their diaspora as a self-descriptive, especially in Sierra Leone. The Yoruba culture was originally an oral tradition, and the majority of Yoruba people are native speakers of the