During the times of his predecessor, Albert of Brandenburg-Ansbach, von Cronberg was the legate to King Sigismund I (the Old) of Poland.

In 1525, when Albert had converted to Lutheranism and was excommunicated, von Cronberg declared himself the next Grand Master.

However, this decision was met with some resistance from the Master of the Livonian branch, Wolter von Plettenberg, who also laid a claim to this function.

The conflict was averted by Emperor Charles V, who settled the matter in 1527 in favour of von Cronberg, declaring him "Administrator of the Office of Grand Master".

He was unsuccessful, however, in preventing further secularization of the Teutonic Order in the Holy Roman Empire, with increasingly more knights breaking the oath, by conversion to Protestantism or disobedience to the Catholic Grand Masters.