Council of Trent – to span twenty-five sessions thru 1563 – opens for the revival of the Catholic Church vis à vis the Protestant Reformation.
(Trent was located inside the Holy Roman Empire, now Italy)
The Council more lucidly re-defines the official Catholic theology and biblical canon.
The Counter-Reformation a.k.a. the Catholic Reformation a.k.a. the Catholic Revival—is generally denoted as spanning the period bracketed by the commencement of the Council of Trent (1545) and ending with the close of the Thirty Years War (1648) 103 years later.
[The next major Catholic ‘Ecumenical’ Council – The First Vatican Council – would take place over 300 years later (also in Rome, but at the Vatican). Its best-known decision was its definition of papal infallibility.]