The most common types of crusade books are those that focus on the First Crusade (because it was successful), on the Fourth Crusade (because it went so badly wrong) and on the entire movement more generally. The three books considered here provide examples of each category, at the same time demonstrating the considerable vitality of scholarship in what is at first glance a thoroughly researched field.

William Purkis revisits the theme of First Crusader ideology and traces its changes during the twelfth century. In contrast to recent scholarship – which emphasises the preeminence of penitence and pilgrimage in early crusader thought – Purkis suggests that the ideal of imitatio Christi was central to the original message proclaimed by Urban ii. In doing so, he shifts the direction of recent scholarship, which has viewed this brand of piety as an invention of monastic writers who applied ‘theological refinement’ to the original crusade narrative. This application of imitatio Christi to the First Crusade, however, may attribute too much sophistication to the movement. In 1096 the words referred not to a Franciscan style of devotion but to the simple act of sewing a cross onto one's garment. The most innovative sections of the book focus on the practice of holy war in Spain. Purkis argues convincingly against those who would find the origins of the crusade on the Iberian Peninsula, proposing instead that it was only in 1120s, at the instigation of Calixtus ii, that crusade preachers begin to describe warfare there as a salvific path equal to Jerusalem. By the 1130s, however, as Purkis shows through a fascinating reading of Pseudo-Turpin and of the Liber sancti Jacobi more broadly, Spanish crusading had developed its own traditions, rooted in legends of Charlemagne and shaped by associations with Compostella.

Similar theological speculation would seem entirely inappropriate to the inescapable ambiguities of the Fourth Crusade, and the eleven essays collected by Thomas Madden do little to dispel that idea. Called in 1199 by Innocent iii to destroy Ayyubid power in Egypt and to regain control of Jerusalem, the expedition ended famously with the sacking of Constantinople in 1204. This turn of events led to speculation, beginning in its immediate aftermath, that some crusaders, most likely the Venetians who had provided the Franks with a massive fleet, had conspired to take control of the crusade and to divert it towards ends more profitable than Jerusalem. Madden observes in his introduction that this ‘diversion question’ has been settled, although in doing so he is perhaps overly hasty. Marco Meschini's analysis of four different Fourth Crusade experiences, for example, is particularly provocative, with its presentation of Innocent iii as essentially disconnected from reality and with its wholly convincing interpretation of the crusade's leaders as fundamentally flawed, always willing to subordinate the expedition's goals to their own immediate financial needs. While Pierre Racine provides a useful overview of Venice's commercial empire on the eve of the crusade and while he suggests that it made little financial sense for the city to attack Constantinople, he probably goes too far in suggesting that the crusade's outcome was for the Venetians an economic misfortune. Both David Perry's examination of the translatio of the relics of St Simon (including an English version of the translatio) and Serban Marin's more wide-ranging analysis of Venetian historiography note that in Venice's historical memory, the Fourth Crusade was not at all a failed expedition to the Holy Land but a wilful act of vengeance against Constantinople. In sum, the diversion question seems now more in need of nuance than elimination. In addition to such politically and economically focused essays, the volume contains several papers examining cultural interactions – Greek, Latin and Arab – sparked by the Fourth Crusade, as well as a fascinating paper by Giulio Cipollone, who suggests that the Fourth Crusade introduced into Innocent's Curia a new sense of tolerance towards outsiders. Together these papers demonstrate how unexpected could be the results of the application of holy war doctrine in the Middle Ages, reminding us as well that even this most studied of crusades still raises troubling ambiguities and exciting research possibilities.

More wide-ranging still is Norman Housley's Fighting for the cross, which seeks to reconstruct a generalised ‘crusade experience’ of medieval knights engaged in warfare in the Holy Land. Not chronological in the traditional sense, Housley instead structures his book around the likely experience of a typical crusader. He begins with an overview of sermons preached to convince warriors to accept such a dangerous and expensive proposition. He then describes the preparations necessary for crusade, the difficulties in marching or sailing to the Levant, the types of warfare practised there, and the conditions of scarcity and suffering so typical of these campaigns. After three more chapters focused on the spiritual, ideological and imaginative aspects of crusading, Housley concludes with an essay on the experiences of warriors returning home and on the attempts both literary and artistic to memorialise their accomplishments. Written in a conversational style, and peppered with memorable anecdotes and beautiful illustrations, the book should prove readily accessible to a non-specialist audience. The thematic focus allows Housley great interpretive freedom, although not without consequence. In particular, one feels the difficulty in studying the crusades in isolation from the general European cultural intellectual climate. Housley's discussion, for example, of the acts of carnage committed during the crusades and his reluctance to attribute them to an anti-Islamic ideology would surely have benefited from a consideration of the recent literature on intolerance and persecution in the high Middle Ages. His discussion of the diminishing role of miracles and visionaries during the later crusades similarly ought to have taken into account broader changes in European conceptions of the natural and supernatural worlds. Whatever the book's shortcomings – and they probably stem from the impossibility of describing the entire crusade movement in a single volume – Housley has crafted a highly readable introduction to the subject, a starting point equally viable for the more focused volumes by Purkis and Madden, not to mention a delightful alternative to the predictable and all-too-dull chronological narratives which still dominate the field.