John O'Malley's reputation as a church historian is solid gold, and so is this book. It has already been dubbed the definitive one-volume history of the Council of Trent, probably for decades to come. O'Malley's narrative is rich in detail and adeptly lays out the politics of reform that engaged the emperor and kings of Europe as well as bishops and theologians, so it flows with the intrigue of a deftly developed suspense story. The cast of characters includes the popes and members of the Curia who, through papal legates, ensured that the much-desired “reform of head and members” (224) resulted in needed episcopal reforms, such as the required residency of bishops in their dioceses, but did not touch the “head,” the papacy and Curia. What may be surprising to readers who have studied Vatican II is the role of the many theologians at Trent. They were given questions from the bishops, who then sat silently to hear the theologians present arguments for as many as six days at a stretch. Only then did the bishops speak.

The agenda was set by Martin Luther, whose challenges concerned (1) justification by faith alone through grace without the works of the law, (2) the principle of sola scriptura as against the Catholic inclusion of tradition to determine doctrine, and (3) his demand for reform of the church, head and members, through a free and open council in German lands. The popes were happy to address the doctrinal challenges posed by the reformers, but did not want to entertain reform of the head and members, a change that Emperor Charles V and others insisted on. This resulted in the dual attention of the council, so that every doctrinal decree was accompanied by a reform decree. Trent did indeed reform the way bishops managed their dioceses: each bishop was to reside in his own diocese and see to the correct teaching of doctrine and administration of the sacraments. To this end, one of the most important reforms of the council was enacted: canon 18, the establishment of diocesan seminaries. Religious orders had seen to the theological, liturgical, and moral training of their members; that requirement was extended to the diocesan clergy. As it gradually took hold throughout the Roman Catholic world, it became one of the most effective of the reforms enacted at Trent.

This book might also be titled Trent: What Happened and Didn't Happen at the Council. Readers will be surprised by how much reform popular opinion has attributed to the Council of Trent, reform that was left open by the council and enacted after the council by popes and the Curia. For example, the use of the vernacular for the liturgy was debated and left open; it was Pope Pius V who, in 1570, published a new Latin Roman missal, with no mention of the possibility of a vernacular version, as desired by many German bishops and debated by the council but left undecided (269–70). Still later, in 1588, Pope Sixtus V established the Congregation of Rites: “The decrees of the Congregation tightly controlled liturgical practice especially as time moved on, and in many people's minds they somehow began to be considered ‘Tridentine’” (270).

Trent is engagingly written; it also provides notes that are helpful to the scholar, and an index. Appendix A presents an outline of the twenty-five sessions of the Council of Trent: the reigning popes in each of the three periods, 1545–49, 1551–52, 1562–63, and the decrees enacted in each of the sessions. Appendix B contains “The Tridentine Profession of Faith.”

I used this book with a parish study group of twenty who enjoyed it, and from their discussion of it, found it congenial and enlightening. It is suitable for undergraduate and graduate classes, and of course, it is a must for libraries.