31 October 1517

Luther's Ninety-Five Theses on indulgences

The Dominican Johann Tetzel was selling indulgences for Archbishop Albrecht of Brandenburg with the permission of Pope Leo X. Outraged by this, Luther drew up in Latin a "Disputation on the Power and Efficacy of Indulgences" – 95 theses. By tradition, he posted them on the door of the Wittenberg castle church on 31 October 1517.

It was originally an academic challenge to scholarly debate. It was aimed at preachers of indulgences rather than the pope himself. Luther's doctrine of justification by faith already removed the very need for indulgences.

Without the author's knowledge the theses were translated into German, printed and spread across Germany. This made Luther a popular hero. The date is conventionally taken as the start of the Reformation.