Hugh of Die was bishop of Die (1073-1081) and later archbishop of Lyon (1081–1106). Pope Gregory VII demonstrated his appreciation for Hugh's reforming vigor and enthusiasm by appointing him as his legate (1074–1085). Pope Victor III (Desiderius of Montecassino) took his legatine commission away, but Pope Urban II reinstated him to a geographically smaller commission in 1094. During the pontificate of Gregory VII he participated in almost all the important church councils and deposed many simoniacal prelates. He made a pilgrimage to Santiago del Compostello in 1095 and to Jerusalem in 1103. In other words, his life was filled with politics, power, ambition, and the burning conviction of a reformer.

There are two main sources for Hugh's life: Gregory VII's papal registers and Hugh of Flavigny's chronicle. There are a few other sources such as Hugh's letter to the Countess Matilda explaining his opposition to the election of Pope Victor III. For the most part we see Hugh through the eyes of others. As his subtitle indicates Kriston Rennie has concentrated his efforts on Hugh's work as a legate. He argues that Gregory's Lenten synod of 1074 in which Gregory appointed Hugh legate was an important moment for Hugh where he embraced Gregory's program for reform. If so, he became more Gregorian than Gregory. In January of 1075 Gregory admonished Hugh that he would rather censure him for mercy than chastise him for being too severe. Someone had appealed to Gregory on behalf of ignorant and unlearned clerics (rudes et indocti) whom Hugh had treated badly. Gregory's concerns and Hugh's behavior became a leitmotif of their relationship. In March 1078 Gregory wrote to Hugh again about how his legate had handled six court cases in which Hugh had rigorously followed the black letter of the law but had failed to exercise the proper moderation of discretion (temperantia discretionis). Hugh had suspended, interdicted, and condemned the bishops of Reims, Sens, Chartres, Bourges, and Tours, mainly on the grounds that all had failed to obey his summons. One wonders from which ineffable delusions of grandeur Hugh suffered. The case of Ralph, archbishop of Tours, is especially interesting. Hugh had rendered an unspecified judgment against Ralph, but Gregory pointed out that he did so without any plaintiffs’ making a complaint. Presumably Hugh acted on the basis of fame or rumor. However, according to the norms of procedure—which Hugh seemed unaware—no one can be condemned without an accuser. This was a fundamental norm in the administration of ecclesiastical justice until the second half of the twelfth century when inquisitorial procedure began to enter episcopal courtrooms. Archbishop Manasses of Reims put forward a particularly unique claim: only a judge born and educated in the city of Rome could judge him. Rennie finds justification for Manasses's claim in the canonical collections, but no collection touched upon the new institution of the papal legate and his relationship to the bishops within his legatine jurisdiction. Indeed, even Gratian included almost nothing in his Decretum about the legate's jurisdictional relationship, and, as Robert Figueira has demonstrated, the decretists’ commentaries on these imprecise texts did little to clarify the legal status of a legate. Pre-Gratian canonical collections could hardly have provided Hugh of Die or his episcopal opponents with much evidence.

As Rennie perceptively points out Hugh “was frequently crossing the phantom boundaries” that Pope Gregory wished he would observe (97). The boundaries that Hugh ignored were trespassed because of legatine jurisprudence did not exist. The norms that would be established for legatine mandates do not emerge until the pontificate of Pope Alexander III when the first general decretals regulating legatine jurisdiction begin to circulate in the canonical collections. Alexander's decretal outlining the jurisdictional relationship between papal legates and bishops was immediately taken up by the canonists in at least twenty-five collections before Compilatio prima (1190) and prompted intense speculation about how far a general legatine mandate could be stretched. However, these questions simply did not yet exist in the eleventh century. Gregory's boundaries and Hugh's incursions into jurisdictional swamps have to be seen, I think, as personal and political rather than legal.

Rennie has written a fine book on a single papal legate that sheds much light on the Gregory VII's pontificate, his reform agenda, and the pope's use of legates to advance his program. If I had a further wish I would have liked it if Rennie had delved more deeply into Hugh's attempts to oppose the election of Pope Victor III (Abbot Desiderius of Montecassino). That period in Hugh's life had nothing to do with his legations and would have been a little off the main topic of the book. Although other scholars have treated Hugh's difficulties with the new pope, readers would have benefitted from a careful analysis of his letters to Matilda, countess of Tuscany and these events, which must have been an important moment in Hugh's career.