History of Africa usually governed by an "oba" and an "iwarefa", a council of chiefs who advised the "oba." by the 18th century, the Yoruba city-states formed a loose confederation, with the "Oni" of Ife as the head and Ife as the capital. As time went on, the individual city-states became more powerful with their "obas" assuming more powerful spiritual positions and diluting the authority of the "Oni" of Ife. Rivalry became intense among the city-states. The Oyo Empire rose in the 16th century. The Oyo state had been conquered in 1550 by the kingdom of Nupe, which was in possession of cavalry,
Yoruba people by a significant proportion of the populations of Nigeria, Benin and Togo. The Yoruba faith, variously known as Aborisha, Orisha-Ifa or simply (and erroneously) Ifa, is commonly seen as one of the principal components of the African traditional religions. Orisa'nla, also known as Ọbatala, was the arch-divinity chosen by Olodumare, the Supreme God, to create solid land out of the primordial water that then constituted the earth and populating the land with human beings molded out of clay. The Yorùbá religion comprises the traditional religious and spiritual concepts and practices of the Yoruba people. Its homeland is in Southwestern Nigeria