Oyo Empire 17th century, Oyo began a long stretch of growth, becoming a major empire. Oyo never encompassed all Yoruba-speaking people, but it was the most populous kingdom in Yoruba history. The key to Yoruba rebuilding of Oyo was a stronger military and a more centralized government. Taking a cue from their Nupe enemies (whom they called "Tapa"), the Yoruba rearmed with armor and cavalry. Oba Ofinran, Alaafin of Oyo, succeeded in regaining Oyo's original territory from the Nupe. A new capital, Oyo-Igboho, was constructed, and the original became known as Old Oyo. The next oba, Eguguojo, conquered nearly all of Yorubaland.
Oyo Empire moved further south, to Ago d'Oyo. Oba Atiba sought to preserve what remained of Oyo by placing on Ibadan the duty of protecting the capital from the Ilorin in the north and northeast. He also attempted to get the Ijaye to protect Oyo from the west against the Dahomeans. The center of Yoruba power moved further south to Ibadan, a Yoruba war camp settled by Oyo commanders in 1830. Atiba's gambit failed, and Oyo never regained its prominence in the region. Oba Atiba otherwise called Atiba Atobatele died in 1859; His son Adeyemi I and the 3rd Alaafin to rule