This episode of Ten Minute History (like a documentary, only shorter) covers the outbreak of the Bohemian Revolt which was what would eventually spiral out of control into the Thirty Years’ War.
The revolt was crushed fairly quickly but sparked intervention by Denmark, who didn’t do too well, and later Sweden who did very well. Both of these were aided by France who decided to get directly involved in 1635.
By 1648 the Holy Roman Empire lay in ruins, with Austria and Spain struggling to pay for the war and rebuild the Habsburg Empire. This war saw the rise of Sweden and France but most importantly saw the foundations of modern diplomacy built.
