The octocentenary of the Fourth Lateran Council, among the most celebrated and studied synods of the medieval papacy, was commemorated with the organisation in Rome of a series of conferences and events between 23 and 28 November 2015, and has led to the publication of a range of works discussing its diverse legacies. Among them is the volume under review, which focuses on the impact of the synod on the treatment of Jewish and Muslim faith groups in medieval Latin Christendom.

The book is divided in two parts. The first section is dedicated to the effects of the Fourth Lateran on Jews; while the second part delves into the influence of the council on some facets of Christian-Muslim relations. This structure is convenient insofar as these two faith groups were differently affected by the Lateran decrees. However, the demarcation comes at the expense of Jewish-Muslim comparativism. The effect of such a separation is softened by the brief general introduction, by John Tolan, that situates the reader in the historical significance of the synod, regarded both as the crowning achievement of Innocent iii's ambitions for reform and crusade, and a key step towards the persecution of minorities and outcasts in Latin Christendom during the late Middle Ages.

Part i contains a lively debate as to the exact significance of canons 67–71 for Jewish communities. Valerie Ramseyer's opening piece describes instances of socio-cultural borrowing and exchange between Jewish and Christian faith groups and holy men in southern Italy prior to the mid-twelfth century. Although not entirely connected to the 1215 synod, the author argues for a common Jewish-Christian religious culture that would disappear after the council. More to the point, Anna Abulafia illustrates how canons 67–71 fit within evolving Christian theological and legal discussions concerning the toleration of Jews. As Abulafia suggests, the lens of Jewish service helped Innocent iii to frame Jews at the Fourth Lateran as submissive to Christianity from a theological perspective (as necessary to validate Christian teachings about Christ and salvation) and in practical terms (in negotiating jurisdiction over the socio-economic and political roles allocated to these groups) (p. 89). Alex Novikoff adds to this debate through his concept of ‘audio-visual Jews’, which he presents in his essay in relation to canon 64, which required Jews (and Muslims) to wear a distinctive garb, or habitus, to avoid unwanted social and sexual mixing. For Novikoff, the public signs of difference are symptomatic of wider trends in Christian society: first, the increasing symbolic importance of public squares and spaces; second, the increasing role of the Jew as unwelcome and potentially disruptive on the ‘Christian stage’ (pp. 62–3).

The remaining two articles in this section explore the practical consequences of the canons for some Jewish communities. Concerning canon 64, Irven Resnick explains how, once the habitus was transformed into a signum, the requirement to wear a marker of religious difference was exported throughout Latin Christendom in order to protect ‘both the physical and spiritual boundaries of Christian society’ (p. 73). None the less, enforceability was problematic, owing both to Jewish acculturation and the jurisdictional competition between the Church and secular rulers. Meanwhile, Rebecca Rist's study of chapter 64(F) of the peculiar Hebrew sixteenth-century account Shebet Yehudah provides insight into collective Jewish understanding of the synod. Rist depicts how Jewish leaders worried about the immediate implications of the 1215 events, rather than grasping the long-term impact of the canons on Christian-Jewish relations (p. 111).

Part ii, which is perhaps less cohesive than the previous section, surveys the place of Muslims in the council. In the initial article in this section Ryan Szpiech highlights how the council failed to consider Muslim beliefs and practices, unlike the First and Second Councils of Lyon (held in 1245 and 1274 respectively) and that of Vienne (1311–12). This lack of originality is particularly striking given Innocent iii's extensive correspondence with Islamic Mediterranean rulers, as well as the creation of the Trinitarian Order for the redemption of captives, as outlined in the piece by Giulio Cipollone. The reason for such an omission might be a consequence, as Yvonne Friedman suggests in the ensuing article, of the centrality of Innocent iii's crusading rhetoric to the character and outcomes of the council.

Seeing the Fourth Lateran as a watershed moment, Szpiech underscores, ‘partially misconstrues the banality of its rhetoric and the unoriginal nature of its categorization of infidelity’ (p. 137). The studies in Part ii thus confirm the difficulty in evaluating the effects of the council on the lives of Muslims. This is never clearer than in the Iberian Peninsula, where the largest Muslim communities under Christian jurisdiction were to be found during the Middle Ages, and which are the subject of the final three articles of the volume. Clara Almagro Vidal emphasises how the enforcement of the canons was particularly problematic for the Iberian military orders and their sizeable Muslim subject communities. It was not the badge or conversion but the regulation of tithes – following canon 53 – that most directly affected Muslim life after 1215. Meanwhile, Ana Echevarría describes the haphazard process by which the rules banning non-Christians from public office, money-lending restrictions or the imposition of badge-wearing eventually entered Castilian royal legislation. Finally, Josep Hernando Delgado suggests how the church reform inspired by the Fourth Lateran may have affected the growth of Dominican and Franciscan preaching in Aragon, and the eventual drive for the conversion of Muslim slaves in fifteenth-century Barcelona.

What emerges from the heterogeneity of views and approaches is an interesting volume that will serve as a practical guide to scholars interested in the manifold legacies of the Fourth Lateran Council. An appendix with a bilingual edition of canons 67–71, as well as a bibliography, will be particularly helpful for readers unfamiliar with the literature. It is a useful companion to other titles appearing in Brepols's Religion and Law in Medieval Christian and Muslim Societies series, which is associated with the project coordinated by John Tolan at the University of Nantes, and its comprehensive online source database.Footnote ¹ Although this edited collection is not the last word on the impact of the Fourth Lateran Council on the legal status of Jews and Muslims in Latin Christendom, it is an informative read and fitting commemoration.