Nobody who has been engaged in the study of medieval history over the past two or three decades can fail to be struck by the recent resurgence of interest in military history. From a subject that was neglected by most practising medievalists, indeed regarded by many as fit only for amateurs, it has moved into the foreground of serious research. The military history of the crusades has benefited a good deal from this revival. This may seem unsurprising to those who view the crusades primarily as wars, but much of the most original recent research into the phenomenon of crusading has focused on its religious characteristics – crusade theology, preaching, devotional practices and associated legal and cultural aspects. R. C. Smail's Crusading Warfare (1097–1193) (1956) has always been treated with great respect by military historians for its methodological rigour and penetrating insights, but for many years Smail's study stood virtually alone as a book-length treatment of the strategy and tactics that were adopted by the crusaders, military orders and settlers in the East. When Christopher Marshall took Smail's analysis forward to the fall of Acre (1291) in 1992, it was tempting to conclude that the military history of crusading was effectively closed as a field of research in which new things could be discovered. That has turned out to be far from the case, and given that michael Prestwich has written both about the military history of western Europe and about the military aspect of crusading, this Festschrift provides a welcome opportunity to undertake a comparative review of the two fields of study.