The career of Hugh of Die, bishop of that see from 1073, and then archbishop of Lyon from 1082 until his death in 1106, was long and important. Hugh worked for, with, and at times in opposition to other great figures of the age, and according to Gregory vii's last testament he was one of three supporters whom that pope suggested as his successor. Hugh's rigour in the cause of ecclesiastical reform during the last quarter of the eleventh century is well known, and his activities as papal legate in those decades touched many of the important questions of the day. It is surprising, therefore, that the bishop/archbishop has received relatively little modern scholarly attention per se. Hugh figures prominently in modern scholarly literature, usually garnering a number of citations in indices of monographs and textual editions concerned with the period. Yet, as Rennie notes (p. 26 n.14), it has been more than a century since a volume has been published that centred on him (i.e. Wilhelm Lühe's in 1898). The fact that within the past forty years two doctoral dissertation, both of which remain unpublished, were devoted to Hugh suggests that others also have noticed this lacuna yet for whatever reason did not fill it with a published volume.

Kriston Rennie's monograph is a step in that direction, dealing with one aspects of Hugh's career, namely his work as a papal legate and particularly the legatine councils that he convened in France. Between the years 1075 and 1099 Hugh assembled fifteen synods in that region, thirteen during the pontificate of Gregory vii and two under Urban ii. These gatherings provide the foundation of this volume, which is based on a doctoral dissertation written at the University of Southampton and at King's College, London. The work opens with an introduction that provides background, including historiography and an explanation of the author's methodology. The study then is divided into the following chapters plus a conclusion: ‘Hugh of Die: bishop, archbishop, and legate’; ‘The legatine office under Gregory vii’, with subsections titled ‘Terminology’, ‘Authority’, and ‘Jurisdiction’; ‘Law and reform: theory and practice’; ‘Legatine education and training’; ‘Towards reform in France’, with subsections “The problem of simony”, ‘Clerical unchastity’, ‘Lay investiture’, ‘The laity's role’ and ‘Dispute settlement and other business’. From time to time reference is made to manuscripts, for example at pp. 70, 11 nn. 24, 28, and p. 113, although the book mainly draws on printed sources. The work concludes with three appendices – a list of Hugh's legatine councils; a chronological list of Hugh's correspondence; and a list of ‘Gregorian’ legates ‘inferred’ mainly from Gregory's Register and the Epistolae vagantes – and a bibliography of primary and secondary sources. In general, the narrative is clear and provides an extended look at an important subject that has been in need of a modern treatment. Many examples could be cited of useful information and of insights found therein, for example the treatment of Hugh's relationship with Pope Urban ii (p. 37); at the beginning of the chapter v, the evidence for the staying power of the Decretum of Bishop Burchard of Worms, a canonical collection put together in the early part of the eleventh century but which continued to be copied in the late eleventh and on into the twelfth century; the significance even into the twentieth century of text preservation in the Decretals of Pope Gregory ix (issued in the year 1234), from Hugh of Die's Council of Poitiers in 1078 (p. 118); and the many clear and competent English translations throughout, which are accompanied with the Latin texts in the notes.

Yet notwithstanding this book's timeliness, there is a lack of concern about sound methodology and about up-to-date bibliography. On p.16, for example, the author alludes to the historiographical tradition of the early modern collections of conciliar acta that culminated in the late eighteenth century with the work of Mansi (Sacrorum conciliorum nova et amplissima collectio). There follows, however, on p.17, a remarkable statement: ‘there is simply no better, critical or more modern edition [of conciliar texts]’. This is simply not true, as works (not cited in the bibliography) of Hourlier, Jasper, Somerville, Blumenthal et al. have shown). It is not true even if the discussion is limited to the pontificates of Gregory vii and Urban ii, and to councils north of the Alps. Similar criticism could be made of the use of the nineteenth-century work of the Abbé Migne, although Migne's Patrologia Latina does not play as important a role throughout as does Mansi (see p.17 n. 51). Using Mansi can lead to serious errors. For example, at the beginning of ch iv, at p. 87, in the treatment of Pope Gregory vii's Lenten Council of the year 1074, Rennie refers to the set of more than twenty capitula printed by Mansi in vol. xx.401-31, as ‘The decrees from this Roman council’. In fact, however, these texts are not Gregorian synodal canons per se but derive from the Apologeticus of Bernold of Constance (ed. F. Thaner, MGH, Libelli de lite [1892] 59ff.). Those chapters of Bernold indeed vibrate with ‘Gregorian’ ideas, but the texts of the legislation from the synod of 1074 are lost. Despite such problems, the general narrative that Rennie offers about Hugh of Die/Lyon contains valuable information. The ‘tabula’ of Hugh's correspondence that is assembled in appendix 2, and the list of ‘Gregorian’ legates that is given in appendix 3, will be particularly useful for scholars in future work on the Church in the late eleventh century.