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 to earth. They became popular with their trading with the Portuguese, which gave them guns for their trade. The Yoruba people were invaded by the Fulani which pushed the people to the South. In the late 1800's, they formed a treaty with the Fulani people and were colonized with the British in 1901. The people who lived in Yorubaland, at least by the seventh century BC, were not initially known as the Yoruba, although they shared a common ethnicity and language group. The historical Yoruba develop "in situ", out of earlier (Mesolithic) Volta-Niger populations, by the 1st millennium BC. Archaeologically,