Duke John of Saxony had placed him on the commission for church visitation in Thuringia, and in 1529 appointed him pastor and superintendent at Eisenach, where for eighteen years he administered church affairs with tact, and fostered the spread of education.
He was against the Leipzig Interim (1548) with its compromise on some Catholic usages, and was involved in controversies and quarrels; with Georgius Merula, against whom he maintained the need of exorcism in baptism; with Osiander's adherents in the matter of justification; with his colleague, Nicholas von Amsdorf, to whom he had resigned the Eisenach superintendency; with Flacius Illyricus, and others.
He lost favour with Duke John Frederic of Saxony, fell into bad health, was deposed (1555) from his offices, and was disappointed in his hopes of being reinstated, after the colloquy at Eisenach (1J56).
The Bavarians did, however, advance, and made for the Eisenach-Gotha region, where the Prussian-Hanoverian struggle was in progress.
Another attempt by the Lorraine family to reconquer their duchy was thus foiled, and at the same time a second imperial army under the duke of Saxe-Eisenach, which had crossed the Rhine by Philipsburg, was shut up in an island of the Rhine and forced to make terms with the French.