Το 1555, ο Κάρολος υπέγραψε την Peace of Augsburg with the Protestant states and restored stability in Germany on his principle of "cuius regio, eius religio" ("whose realm, his religion"), a position unpopular with the Spanish and Italian clergy.
In 1555, Charles signed the Peace of Augsburg with the Protestant states and restored stability in Germany on his principle of "cuius regio, eius religio" ("whose realm, his religion").