The bisthum of Münster had been a German country governed by the Catholic church for many centuries. Since the Sacco di Roma however, pilgrims returning from Rome with the bad news had spread discontent in Germany. The break came in 1475: When king Heinrich VIII secularized and annexed the bistums of Augsburg and Trient for his lands, the HRE fell into a kind of Civil War. All the princes tried to annex the clerical lands, which led to lots of confusion and little wars for said lands, which are subsumed as the Twenty-Year War. Note that Münster was named after its capital Münster.