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 to earth. They became popular with their trading with the Portuguese, which gave them guns for their trade. The Yoruba people were invaded by the Fulani which pushed the people to the South. In the late 1800's, they formed a treaty with the Fulani people and were colonized with the British in 1901. The people who lived in Yorubaland, at least by the seventh century BC, were not initially known as the Yoruba, although they shared a common ethnicity and language group. The historical Yoruba develop "in situ", out of earlier (Mesolithic) Volta-Niger populations, by the 1st millennium BC. Archaeologically,