The Council of Piacenza convened by Pope Urban II in March 1095 is perhaps most famously known as the start of what would become the First Crusade. Such a view, however, minimizes the significance of this council, which needs to be seen in the context of a number of important reform councils held by Urban II following his elevation as pope in 1088. In the early years of his pontificate in which he was unable to maintain a presence in Rome as a consequence of the Wibertine schism, Urban convened church councils in southern Italy at Melfi (1089), Benevento (1091) and Troia (1093) as a means both of continuing the reform of the Church and of establishing his authority as the legitimate pope. Urban would continue this practice throughout his pontificate, holding councils at Piacenza, Clermont, Nimes, Bari and Rome. This new book by Robert Somerville, who has devoted much of his career to the study of Urban II, enables us to see the council of Piacenza and its legislation in its historical context and complexity, thereby deepening our understanding of Urban's role in the history of conciliar activity and the dissemination of conciliar decrees.

The volume is divided into six chapters. In the introduction, Somerville begins by underlining the argument advanced in his earlier books: The Councils of Urban II, i: Decreta Claromontensia (1972), Pope Urban II, the Collectio Britannica and the Council of Melfi (1996, with Stephan Kuttner) and elsewhere, of the significance of Urban II's councils in marking a transition of papal control over conciliar activity. Arguing that Piacenza was the ‘general council’ that Urban had long wanted to convene, he outlines the attendees and the range of cases and introduces the sources from which we derive our understanding of what happened at Piacenza. Chapters 2–5 are then devoted to an extensive assessment of the legislative programme of the council. Chapter 2 considers in detail the extant sources for Piacenza: Bernold of Constance's Chronicon, the Gesta Romanae aecclesiae contra Hildebrandum, the lists of the legislation, known as the textus receptus, which are sometimes introduced by a preamble and usually include fourteen or fifteen decrees that circulated in manuscripts and canon law collections as well as other literary sources including Gerhoh of Reichersberg and the Annalista Saxo. In the first part of this chapter, Somerville analyses the problems of the different if not entirely contradictory accounts of Bernold and the Gesta, whilst in the second he discusses the survival and transmission of the textus receptus in the Polycarpus tradition, in some thirty twelfth-century manuscripts and in canon law collections. Here he underlines the fact that the survival of the legislation from Piacenza rests on several dozen twelfth-century manuscripts that present essentially the same canons, and although not all copies contain all the decrees, most include the stipulations about simony and simoniacal/schismatic ordinations, issues that had confronted the reformers since the start of the Wibertine schism in 1080. The brief chapter 3 considers the historiography of Piacenza from Baronius to Weiland, the last editor of the legislation in 1893. In chapter 4, Somerville explores the transmission of the canons, elaborating in more detail the variant forms across the surviving texts. This chapter includes the edition of the legislation from Piacenza with a full apparatus criticus at pp. 85ff. and an English translation. Chapter 5 then focuses on the content of the decrees and looks to situate them within the context of Urban II's pontificate and the framework of his other councils. Noting that simony and the ordinations of simonists and schismatics lay at the heart of the programme at Piacenza, Somerville contends that Urban may have been seeking to promote measures for handling simoniacal and schismatic orders with some judicious dispensations in an effort to break the schism by disenfranchising its hierarchy. The final chapter looks at the legislation from Urban's councils from the time of Piacenza to that held in Rome in April 1099 just months before his death. The volume includes a somewhat modest bibliography and it was a source of regret that not all the literature cited in the notes is found there.

This is an important study for a number of reasons, not least of all the new critical edition of the decrees. The book also emphasizes the extent to which the problems of the schism with its rival hierarchy and ordinations seriously continued to challenge the Latin Church throughout Urban's pontificate. Most important for the present reviewer is the extent to which Somerville highlights the difficulties faced by the later eleventh- and early twelfth-century papacy in disseminating its legislative programme, difficulties no doubt complicated by the papal practice of repromulgating decrees from earlier councils. None of the extant accounts of Piacenza derives from the papal chancery. Somerville compares this with Melfi where the transmission was more secure but also refers to Clermont where the transmission is notoriously torturous. That this problem would continue is amply shown by the widely varied transmission of the decrees of the Third Lateran Council (1179).

Yet a sense of what happened at Piacenza in 1095 and at other eleventh- and twelfth-century councils was certainly known across Europe. Indeed as the Gesta reveals, the content of the legislative initiatives was a matter of considerable debate, something to which the variants may also point. Popes such as Urban II were increasingly able to use church councils to handle all matter of ecclesiastical business, to propagate reform measures, and to introduce and/or clarify doctrinal and liturgical practice. Although the popes may well have attempted to transmit the legislation of their councils uniformly across western Christendom, the survival of the proceedings mostly relied on participants bringing either verbal reports or their own notes home. These individualistic and idiosyncratic variations, in the end, offer us a richer understanding of the possibilities for diversity of opinion and approach and even outright resistance to the ambitions of papal councils such as that at Piacenza.