THIRTY YEARS' WAR. — In 1608 the German Protestants formed the Evangelical Union, against which there arose the following year the “Catholic League.” In 1618 the Defenestration of Prague was the signal for a political and religious revolt of Bohemia against the Habsburgs: the Bohemians sought aid from the Evangelical Union and elected as their king Frederick, Elector Palatine. But he was defeated in 1620 by Ferdinand II; there followed, under the auspices of the Catholic League, a vigorous campaign of “re-Catholicization” that extended into Austria and Silesia. The Evangelical Union was dissolved.
To curb the excessive power of the Habsburgs, Richelieu, while fighting the Huguenots in France, encouraged the intervention of Christian IV of Denmark against the Empire; Christian was placed at the head of the reconstituted Evangelical Union, but, defeated by Wallenstein, was forced to make peace. France then provoked the entry into the war of Gustavus Adolphus of Sweden, who, after defeating the Imperials at Leipzig, fell on the field of Lützen (1632). In 1635 the Emperor concluded with the German Protestants the Peace of Prague, which suspended for forty years the Edict of Restitution. To this peace neither France nor Sweden adhered. Now Richelieu, having subdued the Huguenots, decided on direct French intervention, declaring war on Austria and Spain. From this moment the conflict lost its original character as a religious war and became a struggle for predominance. The French won at Rocroi (1643) and at Freiburg, while Mazarin, with his diplomatic arts, isolated the Habsburgs. In 1648 several peace treaties were concluded in different localities (Munster, Osnabrück) that go under the collective name of the Peace of Westphalia. By this France obtained Alsace and was confirmed in possession of the three bishoprics of Metz, Toul, and Verdun. Sweden and Brandenburg increased their territories. Switzerland and Holland were recognized as independent. The treaty settled the religious question by granting an amnesty for occupied properties. By granting toleration to Protestants, it sanctioned the rupture of the religious unity of the Christian world.