Diet of Augsburg

The Diet of Augsburg were the meetings of the Reichstag of the Holy Roman Empire in the German city of Augsburg. There were many such sessions, but the three meetings during the Reformation and the ensuing religious wars between the Catholic emperor Charles V and the Protestant Schmalkaldic League in the early 16th century are especially noteworthy.

The session of 1530 attempted to calm rising tensions over Protestantism. After the Edict of Worms had condemned Lutheranism, problems of enforcement emerged during the 1520s, as Charles V's wars against France and commitments in the rest of his empire prevented him from focusing on German religious problems. In 1529, however, he signed a successful peace treaty with France. After these successes, Charles aimed to assert his control over what he saw as German religious heresies. It brought forth the Confessio Augustana, a central document of Lutheranism that was presented to emperor Charles V.

After his victory over the Schmalkaldic League, Charles V convened the session of 1547/48 (geharnischter Reichstag), where the Augsburg Interim was proclaimed. This attempt to give Catholicism the priority was rejected by many princes, though, and a resolution of the confessional tensions was only achieved at the session on 1555, where the Peace of Augsburg was concluded. The treaty acknowledged the Confessio Augustana and codified the cuius regio, eius religio principle, which gave each prince the power to decide the religion of his subjects.

The decrees of the Council of Trent were acknowledged in Italy, Portugal, Poland, and by the Catholic princes of Germany at the Diet of Augsburg held in 1566.