By August 1522 he became convinced that the time was ripe for action, and issued a manifesto proclaiming that the feudal dues had become unbearable, and giving the impression that he was acting as an ally of Luther, although the latter knew nothing of his intentions and would have heartily disapproved of his methods.
Sickingen's first march was against Treves.

The archbishop's "unchristian cannon" forced him to retire from this city.

On October 10 the Council of Regency declared him an outlaw.

A league formed by Treves, the Palatinate and Hesse, defeated him and captured his castle at Landstuhl in May, 1523.

Mortally wounded he died on May 7.
Alike unhurt and unhelped by such incidents as the revolt of the knights, the main current of religious revolution swept onwards.