<span>Many believed the Church needed to be reformed. In the 1500s Kings such as Charles V had a sole political strategy: centralisation. This 'centralisation' included forming one State religion throughout the empire. However followers of Calvin and Luther (generally Protestants) were not very pleased with this. God was in their eyes more important than the sovereign. A King strenghtening his centralisation policy of setting Catholicism as the sole religion, consequently sparked political conflicts in the empire as well.
For example, the area what we nowadays call Germany existed in that time from seperate semi-sovereign areas headed by a so-called 'elector'. Electors chose the ruling emperor/king. In 1555 the Peace of Augsburg was signed as a direct effect of the wars between the ultimate sovereign and the semi-sovereign electors. Charles V agreed upon the division of religion within his empire ("cuius regio, eius religio"): the ruler dictated the religion of the ruled in the seperate areas that made up the Holy Roman Empire (HRE).
So, the reformation led to warfare because of different ideas by the ruler and his people. That led to political conflict mainly because the people also didn't agree with the ruler's centralisation policy.</span>
