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,
Oyo Empire Ajele. These were agents appointed by the Alaafin of Oyo to oversee his interest and monitor commerce. The lead representative of Oyo in the corridor was the Olu, ruler of the town of Ilaro. Ajaland was the last layer added to the empire. It was the most restive and distant, and kept in line with threats of expeditions against it. This territory extended from the non-Yoruba areas west of the Egbado Corridor far into Ewe controlled territory in modern Togo. This area, like all tributary states, was allowed a fair degree of autonomy as along as taxes were paid, the