Groups of lay person in the Middle Ages, dedicated to living an above-ordinary life of prayer and mortification in the world. They were founded in the twelfth century in the Netherlands, mostly among the craft guild workers of the day. Each community had a common purse, property, and one hose for shelter. After two centuries of edifying behavior, abuses crept in and heretical policies were adopted. Censured by the Pope and their bishops and warned by the Inquisition, they would not relent and so were condemned. After the French Revolution they practically disappeared.