At the Council of Clermont in November 1095 Pope Urban II called the west to war. His speech was acerbic and vitriolic, religiously charged and filled with the alleged horrors suffered by Christians living in the east. It evoked in his audience a zeal and spirit that would be seen by later generations as the crusading ideal. However, it also exposed inherent political fragility, and deep seated racial biases, amongst elements of his audience, and upon those who took up the cross in the name of Christ. From April to July in 1096 the Ashkenazic Jews of Speyer, Worms and Mainz were targeted by elements of these Christian forces, facing either forced conversion or death. It is worryingly easy to see anti-Jewish sentiment in the central and later Middle Ages. But it is not enough simply to accept it, nor is it appropriate to simply see in medieval Christianity a consistent core of what would become anti-Semitism. The reality is of course much more complex and shifting than such a generalized image would dictate. Those in the People's Crusade who attacked these Jewish communities were engaging with Christian rhetoric and teaching, but also were exposing inherent social and political fear and resentment. Those who were attacked turned to one another for help, but also looked to episcopal authority to curb the horrific violence of the armed pilgrims and the local townsfolk who stood with them.

A study that links the origins of anti-Jewish Christian sentiment to the manifestation of anti-Semitism in the modern period is both welcome and necessary. Robert Chazan asks challenging questions of the Christian past, examining the relationship between anti-Jewish thought in the early church and the anti-Semitism of the modern era. This important reassessment of Christian perspectives on Judaism allows Chazan to reach a thought-provoking conclusion, recognizing a shift from the nuanced and balanced perspective visible in early writings to the much more destructive and acerbic attitudes of the later Middle Ages. His final words are clear: “[t]hese medieval thinkers thus served as a destructive conduit between the anti-Judaism of antiquity and anti-Semitism of modernity” (247). There is then much to praise here. Chazan writes with confidence about each figure selected, and provides thoughtful summaries of each topic and chosen area as he traces the development of anti-Jewish thought. The argument presented is in one sense convincing. The later medieval attacks upon Jewish communities, faith, and history must surely be seen as providing the embryonic form of later anti-Semitic attacks and rhetoric. This is persuasive, all the more so because Chazan recognises the incongruity of the Church leaders (who sometimes presented nuanced and balanced discussion of the Jewish peoples) and the public demonization of them that seemed to cut across social boundaries as reflecting immediate local concerns. The link between the early anti-Jewish sentiment and this later more reactive and violent anti-Jewish belief is less clear, although good effort is made throughout the chapters to tackle this.

The book is divided into two sections. The first looks to the early Christian interpretations of the Jewish past, present and future (a triad repeated throughout the book). There are chapters here on the Synoptic Gospels (3–22), Paul (23–46), Eusebius and Augustine (47–75; 76–108). Sections of each are admirable and full of important ideas and observations, but there are some differences in quality here. The chapter on Paul is the strongest. Here Chazan importantly places Paul firmly against his immediate background, recognizing the ways in which he praises and condemns the Jewish people and how that reflects shifts in his thought. Paul's nuanced and complex arguments are explored with care and overall Chazan provides a clear and persuasive interpretation of Paul's work. The chapter on Eusebius is also impressive, recognizing the issues facing the Christian community of Caesarea and a Christianity that was still seeking to define itself in the fourth century. The chapter on Augustine is fluent and persuasive in parts, but would have benefitted from a much tighter structure. The chapter on the Synoptic Gospels closes well (e.g. 18–21), but would have benefitted from a more rigorous line of argument throughout. Overall, the first section of the book provides a good indication of the different ways in which Christianity thought about and approached Judaism.

The second section turns to the later Middle Ages and considers the Crusading period (109–135), engagement with Jewish sources (136–169), slanderous writings (170–200) and finally Martin Luther (201–236). This is where Chazan's argument begins to take much greater shape, as his interpretation of the evidence supports the link between medieval attacks upon Judaism and the subsequent politicisation of anti-Semitism in the modern period. In writing of the Crusading world Chazan demonstrates his mastery of the material and of contemporary Christian engagement with Jewish writings. Chapters five and six are both excellent, and the conclusions offered entirely convincing. The discussion of slander is intriguing, but rather more could have been made of those immediate circumstances surrounding the Fortalitium fidei. The discussion of Luther, which traces the gradual but dramatic shift in his relationship to Judaism, is admirable and recreates very well Luther's thoughts and ambitions.

The main criticism I have of this work is two-fold. First, the rationale behind the selection of writers and writings needed to be defended and explained with greater diligence. In selecting, in Part I, the Synoptic Gospels, St Paul, and two of the Church fathers, Chazan is able to provide an informed and eloquent examination that recognizes balance and nuance. However, the scholarly rationale is not set out as clearly as needed to fully explain the inherent connections between these texts and those that came later. The epilogue is better at this than the prologue, but this explanation would have been more useful had it been set out much earlier. Second, the leap from Augustine to Peter the Venerable and the Crusading period is too great. It ignores crucial moments and writers in between that would have supported parts of the argument being made, and it does not account for the different ways early medieval Christianity used, thought about and drew upon Judaism. The most significant absence here is a discussion of the Carolingian world. Charlemagne and his successors, and the intellectual court around them, were aware of Jewish history and drew heavily upon the Old Testament in redefining themselves and their society. The language of politics, the role of bishops as watchmen, and the redefinition of kingship drew upon, and were shaped by, intellectual engagement with ancient Israel. Alcuin and Carolingian intellectuals referred to Charlemagne as both David and Josiah, cast the empire as both the New Rome and the New Israel, and produced two new versions of the Bible. Their absence here is unfortunate and weakens the earlier section of the book. The only other criticism is a minor one: the use of scholarship is in parts inconsistent. There are moments where Chazan spends too much time drawing upon and thinking about the methodological approaches and historical interpretations of other scholars, instead of doing what he does best: deconstructing and clarifying the subtle messages of ancient and medieval writers.

To close, this is an important book on an important topic, particularly in the second half where Chazan demonstrates quite clearly the link between modern anti-Semitism and medieval anti-Jewish thought. As he writes: “[u]nder the special circumstances of medieval Europe and its Jewish minority, a new sense of Jews as both religiously opposed to Christianity and socially and economically dangerous to Christian society evolved at the popular level” (247). Chazan must here be right. Later medieval Christians created a dominant and deeply unsettling interpretation of Judaism that stood apart from the explorations of late antique Christian thinkers, and led to the vile hatred that still lives across Europe. There is still much to say on this topic, but I have no doubt this book will become essential reading for those who approach it.