In December 1542, he was appointed administrator of the Bishopric of Brixen,[3] and shortly afterwards, during the same year, he was raised to the dignity of a cardinal by Pope Paul III. Having resigned his bishopric at Trento in 1567 in favour of his nephew Ludovico, he spent the latter years of his life in Italy, and became Cardinal Bishop successively of Sabina, Palestrina, and Porto.[1] A few years after his death, his remains were entombed in the family chapel, in the church of Sant'Onofrio, Rome.
Charles V and his brother, King Ferdinand I, afterwards emperor, esteemed him very highly and employed him in many important and delicate missions. He took an active part in the imperial Diet of Ratisbon as representative of the emperor, and upheld strenuously the Catholic teaching against the heresy of Martin Luther.
Madruzzo was also governor of Milan for 20 months.[4]
As cardinal, Bishop of Trent, and temporal ruler of that principality, he played a prominent part in the Council of Trent. Among other things he insisted that the reform of the Church should be taken up in earnest, a matter much desired by Charles V, and by which it was hoped to win the Protestants back to the Church. It was largely due to his efforts that this subject was discussed and enactments of that character were passed in each session together with decisions on doctrinal matters. During the Council, he opposed Cardinal Pacheco and others who wanted to ban all vernacular translations of the Bible. He was also intent upon promoting a truly religious and Christian life among both the people and the ecclesiastics under his jurisdiction. He was himself cultured and learned, and patronized the liberal arts and learning.
