In the Middle Ages people were afraid of dying, because if you had been a bad person you could go to hell. There was a way to make sure you have a good chance of going to heaven: pay someone to pray for you. These 'tickets' were called indulgences (aflaten). This got a bit out of hand and people started making profits off selling these. Pardoners travelled around, preaching, and sold these indulgences to people who wanted forgiveness for their sins. They could be very expensive too!