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
Oyo Empire After this, Oba Orompoto led attacks to obliterate the Nupe to ensure Oyo was never threatened by them again. During the reign of Oba, Ajiboyede, he held the first Bere festival, an event to celebrate peace in the kingdom. Celebrated regularly, it would retain much significance among the Yoruba long after the fall of Oyo. Under his successor, Abipa, the Yoruba repopulated Oyo-Ile and rebuilt the original capital. Despite a failed attempt to conquer the Benin Empire sometime between 1578 and 1608, Oyo continued to expand. The Yoruba allowed autonomy to the southeast of metropolitan Oyo, where the non-Yoruba areas