As Bishop of Kraków, he was concerned with the level of education of the clergy, was a supporter of a soft approach with dissenters. In 1546, he ordered an inspection visit of the diocese, which in concept at least, was to limit the influence of the Reformation, but due to the mildness of his character was largely ineffectual.
He called a diocesansynod in 1547 at Wiślica but the resolution of the Synod has not been preserved.
He gathered around him scholars and poets such that the atmosphere of the cathedral was one of vigorous scientific and literary debate.