In 1457, Tsoede, 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 Yoruba king for over 70 years other than Tsoede descendents until Ofinran became Alaafin in 1542.
After taking over, many Nupe and Igala were captured and sóld into slàvery, while some escaped to other locations. But Tsoede was an Igala Prince from Idah who became the first king of the United Nupe Kingdom. He mostly used the Igala warriors given to him to by Attah from Idah as he later made each of the 12 Chief.
Tapa people of Ibarapa North Oyo state are Nupe and Igala descedants of those warriors though identified as Yoruba today.
They are the foundation of Yemoja deity in SouthWest.
