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 despite its violent creation, it was held together by mutual self-interest. The government was able to provide unity for a vast area through a combination of local autonomy and imperial authority. Unlike the great savannah empires, of which Oyo may not be called a successor since it was a successor of Ife, there was little if any Muslim influence in the empire. It is known that at least some Muslim officials were kept in Metropolitan Oyo, and men capable of writing and calculating in Arabic were reported by French traders in 1787. Many believe the decline of the Oyo empire