It is pivotal to note that the rich culture of the Yoruba's cut across the shores of Africa and even to Southern America. Oyo Empire was well known for it's industrial productions in brass making
The Alaafin was the apex ruler of the Empire. Although not autocratic in nature, (due to the established system of checks and balances), he was undoubtedly a driving force in the growth of the Empire.
(army of horsemen)
As with all nations, too much wealth often leads to strife, jealousy, and conflict amongst it's rulers. Oyo was no exception. The increase in the empire's wealth brought about this conflict.