The Oyo Empire was a Yoruba empire in West Africa. It was located in present-day western Nigeria and Benin. It grew to become the largest Yoruba-speaking state through the organizational and administrative efforts of the Yoruba people, trade, as well as the military use of cavalry. The Oyo Empire was one of the most politically important states in Western Africa from the late-16th to the early 18th century and held sway not only over most of the other kingdoms in Yorubaland, but also over nearby African states, notably the Fon Kingdom of Dahomey in modern Benin to its west.