Simons became an Anabaptist leader, and was so passionate he was labeled a heretic. His followers were known as Mennonites. • Pope Leo X (1475–1521): Pope. Luther was excommunicated by Pope Leo X in 1521. • Thomas Cajetan (February 20, 1469–August 9, 1534): Cardinal, Philospher, Roman Catholic, Theologian. Cajetan was an Italian philosopher, theologian, and cardinal. He was a Roman Catholic, and most known him from his role opposing the teachings of Luther and his Protestant Reformation. •