Which institution in the pre-colonial Benin Kingdom served as the king's advisory council and was composed of hereditary chiefs?

The Uzama Nihiron was the highest council of hereditary chiefs in the Benin Kingdom, responsible for advising the Oba, installing new Obas, and checking royal excesses. The Ogboni was a Yoruba institution, the Oyo Mesi was the council in the Oyo Empire, and Ekwe was not a significant council in Benin's political structure.