Other responsible positions were entrusted to him, and he was soon one of the most trusted of the ministers of Charles V, whom he accompanied during the War of the League of Schmalkalden in 1546.
Andre ansvarlige stillinger blev betroet ham, og han blev snart en af ​​de mest betroede blandt ministre for Karl V, som han ledsagede under krigen mod det Schmalkaldiske forbund i 1546.