The Peace of Augsburg is signed in Augsburg by Charles V and the princes of the Schmalkaldic League.
The Peace of Augsburg, also called the Augsburg Settlement, was a treaty between Charles V, Holy Roman Emperor, and the Schmalkaldic League, signed in September 1555 at the imperial city of Augsburg. It officially ended the religious struggle between the two groups and made the legal division of Christianity permanent within the Holy Roman Empire, allowing rulers to choose either Lutheranism or Roman Catholicism as the official confession of their state. However, the Peace of Augsburg arrangement is also credited with ending much Christian unity around Europe. Calvinism was not allowed until the Peace of Westphalia.
The Peace of Augsburg has been described as "the first step on the road toward a European system of sovereign states." The system, created on the basis of the Augsburg Peace, collapsed at the beginning of the 17th century, which was one of the reasons for the Thirty Years' War.