Innocent III (r.1198-1216) has long been thought the greatest pope of the high Middle Ages - the high point of papal power and papal claims over the secular world. In pursuit of his theory of papal monarchy, he excommunicated King John of England, deposed Emperor Otto IV of Germany and forced King Philip Augustus to take back the wife he had repudiated. He launched both the Fourth and the Albigensian Crusades. He convened, and dominated, the Fourth Lateran Council (1215), one of the most important theological conferences of the medieval period. he gave St Francis permission to start an order of preaching friars, who became the Franciscans. No other pope, in pursuit of papal supremacy over secular states, dared or achieved so much - though history was subsequently to make his political victories hollow. This book a reassessment of his complex and many-faceted career. It examines Innocent's background and complex character, studying his record as a temporal ruler struggling to establish a firm hold on the papal states. It considers the influences on him, tracing the development of his though, showing how he was influenced by the past and where he was an original thinker. It also explores his response to the rising challenge to religious orthodoxy in Western Christendom - his attitude to the crusading movement (both his crusades turned out to be against Christian communities) and his involvement with the new preaching orders.