The Council of Trent concludes its discussions on the Catholic Church Counter-Reformation on December 4, 1563. The decrees of the council were later confirmed by Pope Pius IV in the bull Benedictus Deus on January 26, 1564.
The Council met intermittently over 18 years beginning on December 13, 1545. It reaffirmed Catholic doctrines on salvation, sacraments, and the biblical canon, while also standardizing the mass, implementing disciplinary reforms and the establishment of seminaries for the proper training of priests and requiring bishops to reside in their dioceses.
