The victories for the Reformation in the Polish-Lithuanian Commonwealth have been gradually canceled by the Catholic Counter-Reformation under the leadership of Stanislaw Cardinal Hozjusz (Stanislaus Hosius), a Prince-Bishop of the Bishopric of Warmia, who dies in Capranica, in the Papal States, in 1579, described by St. Peter Canisius as the most brilliant writer, the most eminent theologian, and the best bishop of his time.

The Jesuits, having arrived in Poland in the 1560s, are developing a network of schools and colleges.

Their greatest preacher, Piotr Skarga, becomes the first rector of the Wilno Academy, the future University of Wilno (now Vilnius, Lithuania), founded in 1579.