Which council declared the Protestant Reformation anathema?

The Council of Trent, which took place between 1545 and 1563, is the council that declared the Protestant Reformation anathema. This ecumenical council was convened in response to the challenges posed by the Reformation, particularly the theological disputes and criticisms of Catholic doctrine led by figures such as Martin Luther and John Calvin. Through its decrees, the Council of Trent reaffirmed key Catholic beliefs, including the authority of the Pope, the importance of tradition, and the necessity of sacraments for salvation.

The council was pivotal in outlining the Catholic Church's response to Protestant reforms, including the establishment of defined doctrines and the reaffirmation of the role of faith and works in salvation. By declaring Protestant teachings anathema, the Council firmly positioned the Catholic Church against the Reformation's interpretations of scripture and theology.

In contrast, the other councils mentioned did not address the Protestant Reformation directly. The First Vatican Council (1869-1870) focused on issues like papal infallibility. The Council of Nicaea (325) primarily dealt with Arianism and the nature of Christ. The Second Vatican Council (1962-1965) emphasized ecumenism and engagement with the modern world, which was a