Oyo, a pre-colonial kingdom in present-day Nigeria, was founded in the 1300s. Established by Oranmiyan of the Yoruba people of West Africa, Oyo quickly grew to become one of the most powerful states in Africa. From its capital city at Oyo-Ile, this weak state in the early 1500s, had by 1550 conquered two neighboring kingdoms, Borgu and Nupe, to become the most dominant political entity in the region.
Oyo was ruled by an Alaafin (king) who shared power with the Oyo Mesi, aristocratic leaders from each of Oyo city’s seven wards. The Oyo Mesi was responsible for the selection of the Alaafin. They could also call for an Alaafin’s suicide if he abused his power.
Under Alaafin (King) Obalokun, Oyo expanded southwestward to the Atlantic coast and became part of the Atlantic Ocean trade system. Trading mainly in slaves, Oyo was able to acquire much-needed foreign exchange. During the seventeenth and eighteenth centuries, Oyo further expanded westward under Alaafin Ajagbo, becoming a major empire, but never encompassing all Yoruba-speaking peoples.
In response to attacks by the Nupe people, Oyo became much more militarized, reorganizing its cavalry and infantry in the sixteenth century. The cavalry became the foundation of the army. Because of its Atlantic ports, Oyo was able to obtain horses for its cavalry from Europe and North Africa.
Oyo’s wealth from trading and especially slave-trading led to debates about the kingdom’s future. Some Alaafin’s wanted to use the wealth to maintain the army and expand the geographic area of the state, others wanted it for conspicuous consumption. These differences led to civil wars as rivals competed for control of the throne and of Oyo’s vast treasury. This period of internal strife ended with Alaafin Abiodun (1754-1789) who reduced the power of the army.
The downfall of the Kingdom of Oyo was rather swift. Abiodun, concerned with little other than grand displays of royal wealth, allowed the Oyo army to disintegrate. This in turn allowed weaker peripheral states to break free of Oyo’s control. One of those states, Dahomey, in the southwest, soon became a political and military rival. Oyo was also affected by the Fulani Jihad waged by Muslims on its northern frontier. Eventually, these provinces broke free as well.
By the beginning of the 19th Century, Oyo lost control of lucrative trade routes which had been a major source of state revenue. By 1837, the kingdom of Oyo had collapsed. A few years later, the remnants of the empire saw themselves under British colonial rule.