Any consideration of the half-millennium of Western European popular enthusiasm from ca. 1000 to ca. 1500—beginning, say, in 994 at the Council of Anse in Burgundy with the intervention of Abbot Odilo of Cluny in the Peace of God movement, and terminating (again with an arbitrary date) on May 23, 1498, in Florence, with the hanging and burning of Fra Girolamo Savonarola, O.P.—must involve the role of the regular clergy, the professed religious of Latin Christendom. Medieval collective religious enthusiasm, especially when it was not inaugurated by ecclesiastical authority, was often divisive, attracting converts and distracting or repelling others. Monks and friars could not remain indifferent to such movements. For one thing, if their stance was deemed inappropriate, their relationship with the laity (perhaps fellow townsfolk), or the papacy, or their rich and powerful benefactors might be compromised. Nor was their role necessarily that of spectators. Members of the regular clergy sometimes participated in medieval revivals. Possibly still more important is the fact that during most of our period the regulars had the lion's share of chronicling popular enthusiasm. It is in their historical writings that medieval popular religious revivals were mythologized and memorialized. Our view of such movements, therefore, has been shaped by their perceptions and prejudices. Their narratives also provide us with a rich source from which to gauge their interpretations of medieval revivalism. For they make no attempt to conceal their attitudes toward lay enthusiasts—their suspicion, animosity, fear, approbation, sympathy, empathy.