During medieval times, penance was not simply saying the Lord’s prayer or the Crede, but involved much physical strain. In order to fully forgive one’s sins at confession, the person was sometimes given the order to walk the Camino de Santiago as penance for their sins. Not all sins warranted this form of penance, just mainly serious and grievous crimes.
During the Spanish Inquisition, the priests thought of four suitable pilgrimages to be used as penance for serious crimes. They were to the Apostles’ Tomb in Rome, the relics of St. James in Santiago de Compostela, St. Thomas’ body at Canterbury, England and the shrine of the Three Kings in Cologne, Germany. And even to this day, there is a tradition at Flanders to award freedom to one prisoner who will complete the Camino de Santiago carrying a very heavy bag under supervision of a guard.