Protestant Reformation

In 1517, the German monk and theologian Martin Luther circulated ninety-five propositions criticizing the way the Catholic Church sold indulgences. What began as an academic protest grew into the Protestant Reformation, a movement that broke the religious unity of Western Christendom, reshaped European politics, and gave rise to new churches that still have hundreds of millions of followers today.

The background was a church that many Europeans felt had grown wealthy, worldly, and distant from ordinary believers. Calls for reform were not new: John Wycliffe in England and Jan Hus in Bohemia had challenged church authority in earlier centuries, and humanist scholars such as Erasmus urged a return to the sources of Scripture. Indulgences, which offered remission of the temporal punishment for sin in exchange for pious acts or payments, had become a particular flashpoint. In the German lands, a campaign to raise funds, partly connected to the rebuilding of St. Peter's Basilica in Rome, drew Luther's anger as a professor at the University of Wittenberg.

Luther's Ninety-five Theses, traditionally dated to 31 October 1517, argued that the practice misled people about forgiveness and that true repentance mattered more than purchased certificates. The popular image of him nailing the document to the door of Wittenberg's Castle Church is famous, but historians debate whether it happened that way; what is certain is that he sent the text to church authorities, including Archbishop Albert of Mainz, and that it spread rapidly. The printing press carried it and Luther's later writings across Germany and beyond, making this one of the first great media-driven controversies in history.

The dispute soon widened from indulgences to the authority of the pope and the sources of Christian truth. Luther came to emphasize salvation by faith alone and the supreme authority of Scripture. Summoned before the Diet of Worms in 1521, he refused to retract his teachings and was declared an outlaw by Emperor Charles V, but he was sheltered by Frederick the Wise of Saxony and translated the New Testament into German. Other reformers, including Huldrych Zwingli and later John Calvin, developed their own versions of Protestant teaching.

The consequences were profound and often violent. German princes and cities adopted Lutheranism for religious and political reasons, the Peasants' War of 1524–25 convulsed the region, and later conflicts, culminating in the Thirty Years' War of 1618–48, drew in much of Europe. The Catholic Church responded with its own internal reforms at the Council of Trent. The Reformation encouraged vernacular Bible reading, literacy, and new debates about conscience and authority, and its effects continue to be felt in religion, politics, and culture worldwide.