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,
Ojigi (Oyo) Ojigi (Oyo) Ojigi (also Ojiji) was Alaafin of the Yoruba Oyo Empire in what is now Nigeria from 1724-1735. Alaafin Ojigi's rule began Oyo's "great age of conquest". His reign is also considered the peak of imperial success, and Ojigi enjoyed the strong support of several important chiefs. Ojigi launched four military incursions against the Kingdom of Dahomey after the receiving requests for assistance from other kingdoms who were threatened by Agaja, the Dahomean king. In 1730 the Dahomeans agreed to begin paying an annual tribute of forty men, women, guns, and four hundred loads of cowries and corals to