By 1600, the German lands were divided by many political and religious rivalries. In 1618, a Protestant revolt in Bohemia set off a series of wars that lasted for 30 years. The wars were partially religious struggles between Protestants and Catholics, but they were also political struggles between certain princes and the emperor. In addition, the kings of Denmark, Sweden, and France entered the wars to gain German lands and to reduce the Habsburgs' power.

The Peace of Westphalia ended the Thirty Years' War in 1648. Under this treaty, France and Sweden received some German lands. The wars had been hard on German trade and farming. Large parts of Germany were ruined, and some of the towns had nearly disappeared. The emperor's already limited power had been further weakened by the wars. Germany was a collection of free cities and hundreds of states.