1531–1555

The Schmalkaldic League, the Schmalkaldic War, and the Peace of Augsburg

On 27 February 1531 Protestant princes and cities formed the Schmalkaldic League to defend against the emperor. The Peace of Nuremberg in 1532 temporarily halted persecution.

Luther died on 18 February 1546. After his death Charles V crushed the League in the Schmalkaldic War, at the Battle of Mühlberg on 24 April 1547. He imposed on the Protestants first the Augsburg and then the milder Leipzig Interim. This provoked bitter adiaphoristic and other disputes within Lutheranism.

A revolt of Protestant princes led by Maurice of Saxony forced the emperor into the Peace of Passau. In September 1555 the Peace of Augsburg established the principle "cuius regio, eius religio" (whose realm, his religion). It recognized only Catholicism and Lutheranism and left the Reformed outside the law. Charles V soon abdicated.