Keywords: Council of Trent; Agreed; Enforcement; Concordats; Diocese.
The article analyses the theme of a Council's authority with regard to the history and application of the Council of Trent (1545-1563). The analysis is conducted, first of all, by examining the complex relationship between the sixteenth-century papacy and the instrument of the Council, looked upon with suspicion by a Roman curia that was increasingly centralized with respect to ecclesiastic dynamics. Secondly, the different times and methods of receiving the Tridentine decrees in the various states and political contexts will be shown, to conclude with their application in the various dioceses. The situation that emerges reveals the complexity of the implementation of the Council in the Catholic world and the need to distinguish, within the very concept of implementation, different levels of meaning and intervention.