For 10 points, name this Church practice of forgiving sins after atonement which were often sold before the Reformation.
They were handed out to those who took part in the so-called "Prussian voyages" as well as to those who fought the Cathars in South-western France. As an incentive, they were given out to participants in any approved passagium generale, and they were a natural extension of taking up the (*) cross. They were first granted en-masse during the Council of Clermont for those soldiers who set out to the Levant. The morality of their granting declined after the Crusades, and "As soon as a coin in the coffer rings / the soul from purgatory springs" was claimed by a Dominican named Johann Tetzel, who was selling these when he entered Wittenberg, heavily upsetting Martin Luther. For 10 points, name this Church practice of forgiving sins after atonement which were often sold before the Reformation.
They were handed out to those who took part in the so-called "Prussian voyages" as well as to those who fought the Cathars in South-western France.
{indulgences}