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,
History of the Yoruba people the settlement at Ile-Ife can be dated to the 4th century BC, with urban structures appearing in the 12th century (the urban phase of Ile-Ife before the rise of Oyo, ca. 1100-1600, is sometimes described as a "golden age" of Ile-Ife). Ife was surpassed by the Oyo Empire as the dominant Yoruba military and political power between 1600 and 1800 AD. The nearby kingdom of Benin was also a powerful force between 1300 and 1850. The Oyo was developed in the 17th century and become one of the largest Yoruba kingdoms, while Ile-Ife remained as a religious significance at the