1618–1648

The Thirty Years' War

The Peace of Augsburg had not covered Calvinists and left the choice of religion to rulers alone. In 1606 disturbances broke out at Donauwörth, and Maximilian of Bavaria forcibly re-Catholicized the town. After this a Protestant Union formed in 1608, and a Catholic League a year later.

In Prague in 1618, Protestants threw two royal councillors out of a window, touching off the war. The Catholic League's army crushed Frederick of the Palatinate, whom the Bohemians had elected king. Bohemia's population fell by four-fifths.

Denmark under Christian IV entered the war in 1625 and was defeated. In 1630 Sweden's Gustavus Adolphus invaded Germany and defeated the League at Leipzig. But he died victorious at Lützen.

After that the war degenerated into plunder and power struggles. Catholic France under Cardinal Richelieu backed the Protestants against the Habsburgs.

The bloodiest pan-European war before the twentieth century ended in 1648 with the Peace of Westphalia.