The Reformation as a movement began on October 31, 1517, when the German monk and theology professor Martin Luther (1483–1546) nailed his Ninety-Five Theses to the door of the Castle Church at Wittenburg (Saxony, Germany). The theses (which are arguments or assertions) questioned the value of indulgences (the pardons that were disseminated by the church) and condemned the sale of them. Luther had already begun to preach the doctrine of salvation by faith rather than by works, and during 1518 he went on to publicly defend his beliefs, which were in direct opposition to the church. The following year he expanded his argument against the church by denying the supremacy of the pope.

In 1521 Pope Leo X (1475–1521) declared Luther a heretic and excommunicated him. Ordered to appear before the Diet of Worms in April 1521, Luther refused to retract his statements of his beliefs, saying, “Unless I am convinced by the testimony of the Scriptures or by clear reason … I am bound by the Scriptures I have quoted and my conscience is captive to the Word of God.” The following month, Holy Roman Emperor Charles V (1500–1558) issued the Edict of Worms, declaring Luther to be an outlaw and authorizing his death. But the Prince of Saxony, known by history as Frederick the Wise (1463–1525), saw fit to protect Luther, whom he had appointed as a faculty member at the University of Wittenberg (founded by Frederick the Wise in 1502). There Luther translated the New Testament into German and undertook a translation of the entire Bible. Luther continued the Protestant movement until his death in 1546.