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 in the Atlantic slave trade Yoruba people in the Atlantic slave trade The Yoruba people, among the most heavily targeted, contributed significant cultural and economic influence upon the Atlantic slave trade during its run from approximately 1400 until 1900 CE. From 1400 onward, the Oyo Empire's imperial success made the Yoruba language a "lingua franca" almost to the shores of the Volta. Toward the end of the 18th century, the Oyo army was neglected as there was less need to conquer. Instead, Oyo directed more effort towards trading and acted as middlemen for both the Trans-Saharan and Trans-Atlantic slave trade. Europeans bringing salt arrived in