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 origin of human civilization, remains intact to this day. The urban phase of Ile-Ife before the rise of Oyo, c. 1100–1600, a significant peak of political centralization in the 12th century) is commonly described as a "golden age" of Ile-Ife. The oba or ruler of Ile-Ife is referred to as the Ooni of Ife. Ife continues to be seen as the "Spiritual Homeland" of the Yoruba. The city was surpassed by the Oyo Empire as the dominant Yoruba military and political power in the 17th century. The Oyo Empire under its oba, known as the Alaafin of Oyo, was active