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
History of the Yoruba people all cases, however, Yoruba monarchs were subject to the continuing approval of their constituents as a matter of policy, and could be easily compelled to abdicate for demonstrating dictatorial tendencies or incompetence. The order to vacate the throne was usually communicated through an "aroko" or symbolic message, which usually took the form of parrots' eggs delivered in a covered calabash bowl by the senators. By the time it was the 19th century, the Kingdom had lost its control of the trade routes. The kingdom of Oyo had fallen in 1837. The Yoruba people believe there are 401 deities. The Yoruba