West Africa a priest-king called as an Eze Nri. The Eze Nri managed trade and diplomacy on behalf of the Nri people and possessed divine authority in religious matters. The Oyo Empire was a Yoruba empire of what is today Western and North central Nigeria. 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
Oyo Empire within and outside of Yorubaland. It was divided into four layers defined by relation to the core of the empire. These layers were Metropolitan Oyo, southern Yorubaland, the Egbado Corridor and Ajaland. Metropolitan Oyo corresponded, more or less, to the Oyo state prior to the Nupe invasion. This was the hub of the empire, where the Yoruba spoke the Oyo dialect. Metropolitan Oyo was divided into six provinces, with three on the west side of the Ogun River and three to the river's east. Each province was supervised by a governor appointed directly by the Alaafin of Oyo. The second