Polish cardinal, one of the most significant figures of the Counter-Reformation.

Consecrated bishop of Chełmno, Pol., in 1549, he was transferred to East Prussia (1551), from where he conducted his campaign by convoking synods, fighting heresy, and rallying Roman Catholics. At the Synod of Piotrków, Pol. (1551), he drafted a profession of faith, later expanded into his celebrated Confessio catholicae fidei Christiana (“Christian Confession of Catholic Faith”), which appeared in 30 editions in his lifetime. In 1561 he was made cardinal and was appointed presiding papal legate to the Council of Trent. He was described by St. Peter Canisius as the most brilliant writer, the most eminent theologian, and the best bishop of his time.