The sixteenth century, which heralded the end of the Middle Ages and the commencement of the Early Modern Era, was a time of tremendous religious upheaval and social ferment. The nebulous conglomeration of movements often referred to as the "Reformation" led to a wave of bloodshed and persecution which engulfed most of Europe for at least a hundred years. The present volume offers a translation of a particularly graphic literary portrayal of tortures and atrocities committed against Catholics during that time—the Speculum Haereticae Crudelitatis [The Mirror of Heretical Cruelty], by Arnold Havens (1540–1610). Havens was a Carthusian monk, an accomplished historian and scholar, and a prolific author. The Mirror of Cruelty is a remarkable and unique literary achievement, describing in gruesome and chilling detail an extensive catalogue of disturbing, inhuman and often bizarre acts of abuse. Most of these have not been available in any English-language sources until now, or have been presented only in abridged and bowdlerized forms. Havens drew the overall plan of his work from another book which enjoyed a wide, underground circulation at the time—the notorious Theatrum Crudelitatum [Theatre of Cruelties], by Richard Verstegan, a kind of nightmarish picture-book of atrocities committed against Catholics. A selection of illustrations from that book are included in this volume.