Thirty-years-war -

It established the "Westphalian System," the idea that a nation has exclusive rights over its own territory and domestic affairs (including religion).

What started as a clash between and Catholic states within the Holy Roman Empire eventually became a "who’s who" of European powers. thirty-years-war

France emerged as the dominant power on the continent, while the Holy Roman Empire began a long, slow decline into a loose collection of independent states. It established the "Westphalian System," the idea that

The war ended with a series of treaties that fundamentally reshaped the world: The war ended with a series of treaties

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

Spain and the Holy Roman Empire fought to maintain Catholic dominance and imperial unity.

Some regions of Germany lost over 50% of their population .