Just over a century ago Heinrich Hagenmeyer published his definitive book on Peter the Hermit. It has shaped most subsequent discussions of Peter’s career, and it must be said at once that no completely new material has come to light since then. There is, however, a problem of perpetual interest posed by the divergences among twelfth-century accounts of the origins of the First Crusade. Until the advent of modern historiography, it was accepted that the expedition was provoked by an appeal from the church of Jerusalem, brought to the west by Peter the Hermit, who had visited it as a pilgrim, had seen a vision of Christ and had been entrusted by the patriarch with a letter asking for help against the oppression of the Christians there. The crusade was on this view born in the atmosphere of pilgrimage, visions and popular preaching which continued to mark its course, and is so evident in, for example, the discovery of the Holy Lance and the visions and messages which accompanied it. Peter is in some sense the embodiment of these charismatic elements, and there is no controversy about his prominence in the history of the movement. He appears as a sensationally successful preacher, who recruited and led a large contingent which left in advance of the main armies, and was cut to pieces in Asia Minor. Thereafter, he appears in the chronicles in a variety of capacities: as a runaway, and an ambassador to the Moslems, as an adviser, as an associate with the popular element among the crusaders, and finally as a guide to the sacred sites at Jerusalem. It is, however, not with these wider aspects of his career that we wish to deal in this paper, but with his special role in the summoning of the expedition. The older view was that he was its first author. Every student of the early church is familiar with militant monks and hermits. It was once believed that Peter, their spiritual descendant, was the most supremely successful of all the ascetic warmongers.