Germany was where the printing press first began to catch on (Gutenberg), and where the Protestant Reformation began (Luther). During the 30 Years War, the population of what we now call Germany fell from 18m to 6m due to war, famine, and plague. It was the battle ground between Catholic forces of the remnants of the Holy Roman Empire and the Protestant coalition led by Sweden. This finally ended with the Peace of Westfalia, which many historians consider the end of that period of turmoil. Religious wars continued however in places like the British Isles.