The Oyo Empire was a Yoruba empire of what is today western Nigeria, north central Nigeria and Western Republic of Benin. Established in the 15th century, the Oyo Empire grew to become one of the largest West African states. It rose through the outstanding organizational skills of the Yoruba, wealth gained from trade and its powerful cavalry. The Oyo Empire was the most politically important state in the region from the mid-17th to the late 18th century, holding sway not only over most of the other kingdoms in Yorubaland, but also over nearby African states, notably the Fon Kingdom of Dahomey in the modern Republic of Benin to the west.