This is an outstanding study of the logistics of the early crusading movement and the ideologies which underpinned them. It is written in an accessible and lucid style aimed at both an academic and non-academic public. Packed with interesting detail, illuminating stories, and profound analysis, there is no aspect of the way in which crusades were prepared and executed that has escaped this author. In five chapters Tyerman takes his readers through what is both a familiar and unfamiliar story. While the narrative of the crusades has been told many times, there is no detailed study of the preparation and logistics involved in getting an armed force together for an expedition to a far-away country many thousands of miles from home. The first two chapters are concerned with justification and propaganda, chapters that set the scene for the contemporary discourse on how to get this unusual type of expedition to the Eastern Mediterranean underway in terms of explanation of why it was needed, how the knowledge of the enterprise was spread and how one could enlist. Ample attention is paid to the rhetoric used to persuade the Christian faithful to join in, especially of course those whose skills were required (ie the warrior class). What crusaders would receive in return is discussed in the third chapter that focuses on recruitment. It is here that the spiritual rewards (ie papal remission of sins) are juxtaposed with the material rewards – only those engaged for religious reasons would qualify for a papal indulgence, while those who went for adventure and material wealth alone were left in a spiritual no-man's-land. Here, too, we find a discussion as to who went on crusade with an admirably fair reassessment of the numbers of women who took part, a gendered approach still so often missing in textbooks on the crusades. The colossal sums involved in the preparation and execution of the crusades is the centrepiece for the fourth chapter entitled ‘Finance’. No one individual could possibly raise the sums involved so groups of crusaders raised the funds from family members (women included), whilst monasteries acted as mortgage lenders in a not entirely disinterested spirit. As the crusading movement grew individual money-lenders became involved, though increasingly they had to chase their customers to get their investment back. As for the fifth and final chapter, on logistics, this is in many ways the pièce de resistance of the book. Here Tyerman successfully tackles the series of interlinked problems arising from the coordination of the many participating groups, such as issues of leadership which was often multiple with lay and ecclesiastical leaders competing with one another. There were also the manifold problems connected with different currencies, languages (preventing intelligibility of orders) and huge distances that slowed down and often broke communication. One subsection, with the modern title ‘health and safety’, analyses the risks involved in long distance military engagement and the unlimited courage and determination that was required to overcome immense problems of supply (of transport, food, drink and arms). A final subsection on strategy discusses the interplay between the military and logistical demands involved. This is a stunning achievement by one of the foremost historians of the crusades. This book is an absolute must for anyone interested in the crusades or indeed any medieval warfare and travel. A brilliant read it is too.