Oyo Empire culture in Oyo where victory was obligatory and defeat carried the duty of committing suicide. This do-or-die policy no doubt contributed to the military aggressiveness of Oyo's generals. The Oyo Empire was the only Yoruba state to adopt cavalry; it did so because most of its territory was in the northern savannah. The origin of the cavalry is disputed; however, the Nupe, Borgu and Hausa in neighboring territories also used cavalry and may have had the same historical source. Oyo was able to purchase horses from the north and maintain them in metropolitan Oyo because of partial freedom from the
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,