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 60,000 in Niger. In the Ivory Coast, they are concentrated in the cities of Abidjan (Treichville, Adjamé), Bouake, Korhogo, Grand Bassam and Gagnoa where they are mostly employed in retail at major markets. Otherwise known as "Anago traders", they dominate certain sectors of the retail economy. The Yorubas are the main ethnic groups in the Nigerian federal states of Ekiti, Lagos, Ogun, Ondo, Osun, Kwara, Oyo, the western third of Kogi and the Akoko parts of Edo. The chief Yoruba cities or towns in Nigeria are: Abẹokuta, Abigi, Ado-Ekiti, Agbaja, Ago iwoye, Akungba-akoko, Akurẹ, Atan-otta, Ayetoro, Ayetoro gbede, Badagry, Ede,