Oyo Empire metropolitan Oyo. This may have been fine in the 15th century when Oyo controlled only its heartland. But to make and maintain farther conquest, the structure underwent several changes. Oyo maintained a semi-standing army of specialist cavalry soldiers called the "Eso", the "Esho" or, formally, the Eso of Ikoyi. These were 70 junior war chiefs who were nominated by the Oyo Mesi and confirmed by the Alaafin of Oyo. The Eso were appointed for their military skill without regard to heritage and were led by the Are-Ona-Kakanfo. After Oyo's return from exile, the post of Are-Ona-Kakanfo was established as the
Egba people Egba people The Egba people are a subgroup of the Yoruba people, an ethnic group of western Nigeria, majorly from the central part of Ogun State that is Ogun central senatorial district. Ogun Central Senitorial district comprises six local government in Ogun state which includes Abeokuta North, Abeokuta South, Ewekoro, Ifo, Obafemi Owode and Odeda Local governments. The Egba group originally under the Oyo Empire became independent following the spectacular collapse of Oyo in the first half of the 19th century. Wars with the Dahomey, in which the Egbas were successful partly due to the protection afforded by the Olumo