Innocent III (elected 1198, died 1216) has long been thought the greatest pope of the high Middle Ages. He launched the Fourth Crusade, sent an army against the Albigensians, and convened the Fourth Lateran Council. In his struggle with the most powerful monarchs of western Europe to assert the supremacy of the spiritual over the temporal power, he excommunicated King John, placed England under an interdict, forced Philip Augustus of France to take back the wife he had repudiated, and had the Emperor Otto IV deposed. But how solid is his reputation? To what extent was he personally responsible for the events of his reign? How far did he influence the massive changes of his time - the claim of the papacy to intervene in European affairs, and to act as universal arbiter and lawgiver? Were the great challenges that he met new? Was it particular circumstances that made it possible for him to leave his imprint on Europe? Who were his advisers? This book is the first reassessment of Innocent's career for nearly forty years. In it, Jane Sayers looks into Innocent's background and complex character. She examines his record as a temporal ruler struggling to establish a firm hold on the Papal States. She considers the influences on him, traces the development of his thought, and shows how he was influenced by the past. She stresses the important part that propaganda played in his dealings with secular rulers, and how firm belief in law led him to attempt the reform of the Church and the regulation of the behaviour of ordinary people through ecclesiastical legislation. Professor Sayers also explores Innocent's response to the rising challenge to orthodoxy - for, by the early thirteenth century, the idea of returning to the simplicity of the early Church, embracing poverty and dispensing with priests, swept over the Mediterranean lands, encouraging lay people to explore the possibilities of an alternative Christianity. Were these movements (Humiliati, Waldenses and Cathars among them) heretical? Could the same forces be channelled within orthodox Christianity? Finally, she considers Innocent's response to the wider world - his attitude to the crusading movement, and his role in the disastrous crusade of 1204, when Christian fought Christian, and Constantinople, the capital of eastern Christendom, fell not to the forces of Islam but to crusaders from the West. Eyewitness accounts and the output of the popes chancery reveal the constant strains on the pope and his government. Innocent faced many crises, but he had the personality to take advantage of opportunities and to rise to meet challenges. He was a pope with a vision of Europe - and Jane Sayers does justice to his complex and many-faceted career in this engrossing study.