Pope John II

Pope John II, who served from 533 to 535 AD, was the first pope to officially change his name upon election, rejecting his birth name Mercurius to adopt a Christian name. His decision marked a significant moment in papal history, symbolizing the church's shift away from pagan associations towards a more distinctly Christian identity. This act set a precedent for future popes, who would follow suit in adopting names that reflect their mission and values.