Churchmen played a vital role in the crusading movement. Crusades were papal instruments and religious wars, and the crusaders, were, at least technically, penitents on pilgrimage who required the services of the clergy to keep them focused on their obligations. At the same time the heterogeneous nature of clerical crusaders makes them a particularly interesting group. They ranged from very senior figures to the chaplains of crusading lords – a class not known for its innate abilities – and to vagabond adventurers. This is a study of the part that they played in crusades to the East between the First Crusade and the so-called Fifth. After an introduction in which the historiography of the movement and past attempts to define crusading are surveyed and the categories of churchmen involved are identified, each crusade and the sources for it are described, before the author turns to analysis. He researches the part that churchmen played in the armies as priests, preachers and pastors; as the organisers of special rites such as processions; as motivators and builders of collective identity; as visionaries; as advisers, arbitrators and negotiators; and as the leaders of their own contingents. Turning to their role with respect to the relations that each crusade had to have with the world around it, he considers the churchmen as intermediaries, particularly with the representatives of eastern Churches , diplomats, missionaries, propagandists and even, although uncanonically, warriors. The book ends with a brief treatment of three figures from the movement: Adhémar of Le Puy, the papal legate, and Peter the Hermit on the First Crusade, and Gottfried of Würzburg on the Third Crusade. The book could be criticised for being somewhat unbalanced, with too much space being given to the First Crusade and an over-reliance on the narrative sources at the expense of the material in cartularies and governmental records, but it is a useful and competent introduction to the subject.