What was Martin Luther charged with?

The initial aim of Martin Luther, professor of biblical studies and Augustine monk, was limited to reform in the use of indulgences. In response, Prierias, Master of the Papal Palace, declared any challenge to the sale of indulgences heretical. Luther proceeded to deny the infallibility of the pope and of General Councils, for which the pope excommunicated him in 1520. However, the Elector of Saxony declined to enforce the Bull of Excommunication, which Luther publicly burnt in the university at Wittenberg. One of the forty one heresies and "pestiferous errors" of which he was accused was the opinion that "the burning of heretics is against the will of the Holy Spirit."