The Catholic victories alarmed Protestants almost everywhere. The victories of the emperor endangered the independence of the German princes, while the French Bourbons were concerned about the growth of Hapsburg power.
The newProtestant leader became King Gustavus Adolphus (r. 1611-1632) of Sweden. In the summer of 1630, the Swedes moved into Germany. Later in the year, France and Sweden signed an alliance, and France entered the war against the Hapsburgs.
The Thirty Years' War had begun prima