The German lands were referred to as "The Holy Roman Empire" in those days. Immediately following the death of Martin Luther, the prominent German leader of the Protestants, war broke out between the forces of the Holy Roman Emperor, Charles V, and Lutheran princes. Charles V went to war against the Lutheran princes in the Smalcald Wars (1546-57) to try to force them back into adherence to Catholicism.
There were ongoing struggles in the years after that, which affected other territories in which Protestant reformers were active. There were wars in Swiss territories as well as in France. Ultimately, the Thirty Years War (1618-1648) was waged in the German territories (aka the Holy Roman Empire) by many of the nations of Europe over religion as well as other issues.
