|Participants||Charles V, Schmalkaldic League|
|Outcome||(1) Established the principle Cuius regio, eius religio.|
(2) Established the principle of reservatum ecclesiasticum.
(3) Laid the legal groundwork for two co-existing religious confessions (Catholicism and Lutheranism) in the German-speaking states of the Holy Roman Empire.
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.
The Peace elaborated the principle Cuius regio, eius religio ("whose realm, his religion"), which allowed the princes of states within the Holy Roman Empire to adopt either Lutheranism or Catholicism within the domains they controlled, ultimately reaffirming their sovereignty over those domains. Subjects, citizens, or residents who did not wish to conform to the prince's choice were given a grace period in which they were free to emigrate to different regions in which their desired religion had been accepted.
Article 24 stated: "In case our subjects, whether belonging to the old religion or the Augsburg Confession, should intend leaving their homes with their wives and children to settle in another, they shall be hindered neither in the sale of their estates after due payment of the local taxes nor injured in their honor."
Charles V had made an interim ruling, the Augsburg Interim of 1548, on the legitimacy of two religious creeds in the empire, and this was codified in law on 30 June 1548 upon the insistence of the emperor, who wanted to work out religious differences under the auspices of a general council of the Catholic Church. The Interim largely reflected principles of Catholic religious behavior in its 26 articles, although it allowed for marriage of the clergy, and the giving of both bread and wine to the laity. This led to resistance by the Protestant territories, who proclaimed their own Interim at Leipzig the following year.
The Interim was overthrown in 1552 by the revolt of the Protestant elector Maurice of Saxony and his allies. In the negotiations at Passau in the summer of 1552, even the Catholic princes had called for a lasting peace, fearing that the religious controversy would never be settled. The emperor, however, was unwilling to recognize the religious division in Western Christendom as permanent. This document was foreshadowed by the Peace of Passau, which in 1552 gave Lutherans religious freedom after a victory by Protestant armies. Under the Passau document, Charles granted a peace only until the next imperial Diet, whose meeting was called in early 1555.
The treaty, negotiated on Charles' behalf by his brother, Ferdinand, gave Lutheranism official status within the domains of the Holy Roman Empire, according to the policy of cuius regio, eius religio. Knights and towns who had practiced Lutheranism for some time were exempted under the Declaratio Ferdinandei. Conversely, the Ecclesiastical reservation prevented the principle of cuius regio, eius religio from being applied if an ecclesiastical ruler converted to Lutheranism.
The Peace of Augsburg contained three main principles:
The third principle was not publicized as part of the treaty, and was kept secret for almost two decades.
The document left some unresolved problems. While it gave legal basis for the practice of the Lutheran confession, it did not accept any of the Reformed traditions, such as Calvinism, nor did it recognize Anabaptism. Although the Peace of Augsburg was moderately successful in relieving tension in the empire and increasing tolerance, it meant that many Protestant groups living in the empire still found themselves in danger of the charge of heresy. (Article 17: "However, all such as do not belong to the two above named religions shall not be included in the present peace but be totally excluded from it.") These minorities did not achieve any legal recognition until the Peace of Westphalia in 1648.
Intolerance towards Calvinists caused them to take desperate measures that led to the Thirty Years' War. One of these was the Third Defenestration of Prague (1618) in which two representatives of the fiercely Catholic king of Bohemia, Archduke Ferdinand, were thrown out of a castle window in Prague.
The principle of ecclesiastical reservation was tested in the Cologne War (1583–1588), which grew out of the scenario envisioned by Ferdinand when he wrote the proviso: the reigning prince-archbishop, Hermann of Wied, converted to Protestantism; although he did not insist that the population convert, he placed Calvinism on a parity with Catholicism throughout the Electorate of Cologne. This in itself came forth as a two-fold legal problem: first, Calvinism was considered a heresy; second, the elector did not resign his see, which made him eligible in theory to cast a ballot for emperor. Finally, his marriage raised the possibility of convert the electorate into a dynastic principality, shifting the balance of religious power in the empire, as Protestants could potentially hold a majority of electorates.
A side effect of the religious turmoil was Charles' decision to abdicate and divide Habsburg territory into two sections. His brother Ferdinand ruled the Austrian lands, and Charles' fervently Catholic son, Philip II, became administrator of Spain, the Spanish Netherlands, parts of Italy, and other overseas holdings.