(1545–63), 19th ecumenical council of the Roman Catholic church, which, in response to the Protestant Reformation, initiated a general reform of the church and precisely defined its essential dogmas. The decrees of the council were confirmed by Pope Pius IV on Jan. 26, 1564, and they set the standard of faith and practice for the church until the mid-20th century.

The need for a council to reform the church was widely recognized during the late 15th and early 16th centuries. The Fifth Lateran Council (1512–17) failed in this regard and concluded its deliberations before the new issues raised by Martin Luther had been articulated (see LATERAN COUNCILS,). As early as 1520, Luther called for a council to reform the church and to settle the controversies that he had provoked. Although many leaders on both sides echoed this appeal, Pope Clement VII feared that such a gathering might encourage the view that councils, rather than the pope, have supreme authority in the church. Moreover, the political difficulties that Lutheranism created for Emperor Charles V made other rulers, especially King Francis I of France, reluctant to support any action that might strengthen the emperor's hand by relieving him of these difficulties.

Pope Paul III was elected pope in 1534 partly on the strength of his promise to convoke a council. After aborted attempts to meet at Mantua in 1537 and at Vicenza in 1538, the council finally opened at Trent, in northern Italy, on Dec. 13, 1545. Sparsely attended at first and never free from political obstacles, the council grew in numbers and prestige over the course of the three periods during which it met.

First Period

(1545–47). In many ways the first period of the council was the most successful. Once the many procedural questions were settled, the council addressed the central doctrinal issues posed by the Protestants. One of the first decrees affirmed that Scripture had to be understood within the tradition of the church—an implicit rejection of the Protestant principle of “Scripture alone.” The long and sophisticated decree on JUSTIFICATION, (q.v.) condemned the PELAGIANISM, (q.v.) that Luther detested but at the same time tried to define a role for human freedom in the process of salvation. This session also addressed, less successfully, certain disciplinary questions, such as the obligation of bishops to reside in their dioceses (see BISHOP).

Second Period

(1551–52). After an interruption caused by a deep political misunderstanding between Paul III and Charles V, the council, in its second period, turned its attention particularly to the sacraments (see EUCHARIST; SACRAMENT,). This session was boycotted by the French but attended by a few Lutheran representatives.

Third Period

(1561–63). Forced to adjourn because of the outbreak of war, the council eventually reassembled for its final period. Disciplinary questions dominated the deliberations, especially the unresolved problem of episcopal residency, seen by many as the key to implementing reform. The skillful papal legate, Giovanni Morone (1509–80), reconciled opposing views and brought the council to conclusion. In 1564, Pius IV published the Profession of the Tridentine Faith (from Tridentum, the ancient Roman name for Trent), summarizing the doctrinal decrees of the council. Despite its length, however, the council never dealt directly with the role of the PAPACY, (q.v.) in the church, an issue raised repeatedly by the Protestants. Among the many theologians participating in the council, the most noteworthy were Girolamo Seripando (1492–1563), Reginald Pole, Diego Lainez (1512–65), Melchior Cano (1509–60), and Domingo de Soto (1494–1560).

Significance.

Besides resolving for Roman Catholics some crucial doctrinal and disciplinary questions, the council also imparted to their leaders a sense of cohesion and direction that became an essential element of the revitalization of the church during the COUNTER REFORMATION, (q.v.). Today historians judge that the council was interpreted and implemented in a narrower sense than the participants intended, and some think that it was of lesser importance in the Roman Catholic revival than other factors of a more spontaneous nature. Nevertheless, the designation Tridentine Era for the centuries in Roman Catholicism between Trent and the Second Vatican Council (see VATICAN COUNCIL, SECOND,) reflects the decisive influence that the council had on the modern Catholic church.        J.W.O., JOHN W. O'MALLEY, Ph.D.

See also CHRISTIANITY,; ECUMENICAL COUNCIL,.