Book excerpt: "When the city was filled with these bonfires, he then combed the city, and whenever he received notice of some public sodomite, he had him immediately seized and thrown into the nearest bonfire at hand and had him burned immediately." This story, of an anonymous individual who sought to cleanse medieval Paris, was part of a sermon delivered in Siena, Italy, in 1427. The speaker, the friar Bernardino (1380-1444), was one of the most important public figures of the time, and he spent forty years combing the towns of Italy, instructing, admonishing, and entertaining the crowds that gathered in prodigious numbers to hear his sermons. His story of the Parisian vigilante was a recommendation. Sexual deviants were the objects of relentless, unconditional persecution in Bernardino's sermons. Other targets of the preacher's venom were witches, Jews, and heretics. Mormando takes us into the social underworld of early Renaissance Italy to discover how one enormously influential figure helped to dramatically increase fear, hatred, and intolerance for those on society's margins. This book is the first on Bernardino to appear in thirty-five years, and the first ever to consider the preacher's inflammatory role in Renaissance social issues.