John W. O'Malley has once again produced a lucid and learned volume of conciliar history. It is best summarized by its subtitle: “the Making of the Ultramontane Church.” The main title emphasizes Vatican Council I (1869–1870), but that gathering in Rome was the culmination of a decades-long development of what the author calls “one of the most remarkable transformations in social consciousness in modern history” (5). This transformation represented a shift from a time when local churches served to counterbalance papal authority, to one when the papacy became the central agent of power in Rome unlike anything previously experienced. O'Malley is singularly well-prepared to present this account. His previous conciliar histories, including What Happened at Vatican II (The Belknap Press of Harvard University, 2010) and Trent: What Happened at the Council (The Belknap Press of Harvard University, 2013) flank this present work, and the three together present a unified and sophisticated understanding of what is arguably the central issue in the history of the Roman Catholic Church since the Renaissance and one that still echoes in the current life of the Roman Catholic Church.

It is initially surprising to see Vatican Council I itself treated in only the last two chapters. O'Malley prepares for those chapters by first addressing the changed circumstances in which the church operated since the Enlightenment. He outlines his narrative and defines “ultramontane” as a “significantly more pope-centered mode” of being (1). In an opening chapter, O'Malley recounts the challenges the Church and papacy faced in the Enlightenment and the French Revolution. Challenges to the papacy by monarchs of the Enlightenment, such as Joseph II of Austria, and supporters of Gallicanism, such as Bossuet in France, asserted the rights of local churches in a far less centralized Church than the papacy would achieve by 1870. These challenges reached a critical stage in the French Revolution which altered the relationship of Church and state that had stood for a millennium.

In chapter 2, O'Malley relates the growth of the Ultramontane movement. This supported “the transformation of the pope's role from testifying to the faith of the church to assuming the more proactive role as the church's primary or even exclusive teacher” (60). O'Malley shows that while Ultramonatanism was influenced by clerical figures such as Felicité de Lammenais and Cardinal Henry Manning, the leadership in the movement was more in the hands of laymen, often enough converts, who had no formal theological training such as Joseph Marie de Maistre and Louis Veuillot. These laymen saw papal primacy and infallibility not as doctrines with long histories but as a solution to what they perceived as a crisis of authority in Europe since the Enlightenment that was as much social and political as it was religious. The Ultramontane program, moreover, was carried forward, most notably not in scholarly journals or university lecture halls but in journals and newspapers, such as Veuillot's L'Univers and the Jesuit's La Civiltà Cattolica, which popularized Ultramontane thought among both clergy and laity and attacked the orthodoxy of Gallican bishops. It was in this context that Ultramontanes made increasing calls for a recognition of papal infallibility.

In chapter 3, O'Malley relates the events and issues that influenced the situation on the eve of the council. These included the revolutions of 1848, the increasing resentment of the population of the papal states towards the rule of the pope, the international cause célèbre that was set off by the papal government's seizure of the Jewish boy Edgardo Mortara in 1858, the proclamation of the dogma of the Immaculate Conception in 1854, the unification of Italy apart from Rome itself by 1860, and the publication of the Syllabus of Errors in 1863. These events formed the background to Pius IX's apostolic letter, Aeterni Patris of 1869 that formally convoked the council.

Chapters 4 and 5 address Vatican Council I itself. By the time it opened, the participants were divided into two broad groups. The majority consisted of those who supported the promulgation of a dogma of infallibility and a minority who were opposed, or at least cautious about, such a decree. As O'Malley demonstrates, the only issue at play was how ultramontane the final decree would be. After long and uncomfortable sessions over the course of the council, in weather at times stiflingly hot and at others very cold, all the while under the shadow of the Italian government's impending seizure of Rome itself, the council fathers moved to establish the decree Pastor Aeternus on papal primacy and infallibility. Pius IX and the supporters of infallibility achieved what decades of advocacy had sought. The majority who favored the decree was not deterred by moderate voices. As the council fathers scattered in the face of the Italian army's arrival they left a papacy greatly enhanced in its primacy and teaching authority while simultaneously deprived of its last vestiges of temporal power.

O'Malley brings a lifetime of expertise to the issue under study. He also acknowledges and draws in particular on the major contributions of Giacomo Martina, author of a three-volume biography of Pius IX (Pio IX, 3 vols., Rome: Editrice Pontificia Università Gregoriana, 1974–1990), and Klaus Schatz author of a three-volume history of the council (Vaticanum I, 3 vols., Paderborn: Schöningh, 1992–1994), neither of which have been translated in English. This excellent volume will be of use both to undergraduate and graduate students and anyone interested in the relationship of religion and culture in nineteenth-century Europe.