Did you know that the Oyo Empire had no Alaafin for 85 years

In 1457, the king of Nupe invaded Oyo and sacked the capital where Onigbogi, the Alaafin (king), fled to the land of the Ibariba and died there. 

The Oyo Empire had no Alaafin for 85 years until Ofinran became Alaafin in 1542.

The origins of the Oyo Empire lie with Oranyan (also known as Oranmiyan), the last prince of the Yoruba Kingdom of Ile-Ife (Ife). Oranyan made an agreement with his brother to launch a punitive raid on their northern neighbors for insulting their father Oduduwa, the first Ooni of Ife. On the way to the battle, the brothers quarreled and the army split up. Oranyan's force was too small to make a successful attack, so he wandered the southern shore until reaching Bussa. There the local chief entertained him and provided a large snake with a magic charm attached to its throat.

The chief instructed Oranyan to follow the snake until it stopped somewhere for seven days and disappeared into the ground. Oranyan followed the advice and founded Oyo where the serpent stopped. The site is remembered as Ajaka. Oranyan made Oyo his new kingdom and became the first "oba" (meaning 'king' or 'ruler' in the Yoruba language) with the title of "Alaafin of Oyo" (Alaafin means 'owner of the palace' in Yoruba). He left all his treasures in Ife and allowed another king to rule there.

At one time, Oyo-ile was at war with the Bariba of Borgu, who wanted to subjugate the new city still under construction. Orangun Ajagunla of Ila, Oranmiyan's elder brother, stormed in with his men to assist. Not long after the war was won, Oranmiyan had a son, Ajuwon Ajaka; much later Arabambi was born by the woman from Tapa (Nupe). It is believed that the name "Sango" was given by his maternal grandfather or he adopted it from the local name for the God of Thunder. Either way the royal family was devoted to The Spirits of Thunder (Jakuta) and War (Ogun).

The Nupe occupation

Oyo had grown into a formidable inland power by the end of the 14th century. For over a century, the Yoruba state had expanded at the expense of its neighbors. During the reign of Onigbogi, Oyo suffered military defeats at the hands of the Nupe led by Tsoede. Sometime around 1535, the Nupe occupied Oyo and forced its ruling dynasty to take refuge in the kingdom of Borgu. The Nupe sacked the capital, destroying Oyo as a regional power until the early 17th century.

Imperial period (1608–1800)

The Yoruba of Oyo went through an interregnum of 80 years as an exiled dynasty after its defeat by the Nupe. They re-established Oyo as more centralized and expansive than ever. The people created a government that established its power over a vast empire. During the 17th century, Oyo began a long stretch of growth, becoming a major empire. Oyo never encompassed all Yoruba people, but it was the most populous kingdom in Yoruba history.

*Later conquest

With its cavalry, Oyo campaigned successfully in conquest and suppression over great distances. The Oyo army was able to attack defensive fortifications, but it was harder to supply an army, and they withdrew when supplies ran out. The Oyo did not use guns in its major conquests. The military waited until the 19th century to adopt them. In 1764, a joint Akan (Akyem)-Dahomey-Oyo force defeated an Asante army. The alliance victory defined borders between the neighboring states. Oyo led a successful campaign into Mahi territory north of Dahomey in the late 18th century. 

The Yoruba also used the forces of their tributaries; for instance, they accomplished a 1784 naval blockade of Badagri with an Oyo-Dahomey-Lagos force.