The Peace of Augsburg was reaffirmed and expanded to include Calvinism, effectively ending the era of large-scale religious wars in Europe.

The war began in Bohemia (modern-day Czech Republic) when Protestant nobles, angry over the curtailing of their religious rights, tossed two Catholic royal officials out of a window in Prague Castle. Remarkably, they survived the 70-foot drop, but the act triggered a rebellion against the Holy Roman Empire. 2. From Religion to Politics

The war was brutal. It introduced "total war" tactics where armies lived off the land, seizing crops and burning villages.