Lutheranism has powerful supporters, but its survival is by no means certain.

Its main opponent is the Habsburg emperor Charles V, who has inherited Spain, the Netherlands, southern Italy, Sicily, and the Austrian lands as patrimony and who hopes to restore the unity of the German Empire by keeping it Roman Catholic.

Charles has been out of Germany between 1521 and 1530, and when he returns he finds that the new religion has won too many adherents to be easily uprooted.

In addition, he cannot devote himself single-mindedly to combating it but also had to struggle with powerful external enemies.

One is Francis I (r. 1515-47) of France, who attacks the empire from the west, having resolved to destroy the power of the Habsburgs.

Another threat is posed by the Turks, who are attacking the empire from the east.

Even the papacy at times conspires against its coreligionist because it fears Charles is becoming too powerful.