Peace of Augsburg (1555): Cuius Regio, Eius Religio

The Peace of Augsburg, agreed on 25 September 1555 at the Imperial Diet in Augsburg, was the settlement that made Lutheranism legal in the Holy Roman Empire. It allowed each ruling prince to choose Catholicism or Lutheranism for his lands, a principle later summed up as cuius regio, eius religio, “whose realm, his religion”. It kept a fragile peace in Germany for more than 60 years, but its gaps helped lead to the Thirty Years’ War.

Background

The Reformation began in Germany when Martin Luther challenged the sale of indulgences in 1517, as told in Martin Luther’s 95 Theses. Emperor Charles V condemned Luther at the Diet of Worms in 1521, but many princes and imperial cities adopted Lutheran reforms anyway.

In 1531 Protestant rulers formed the Schmalkaldic League for mutual defence. Charles, long distracted by wars with France and the Ottoman Empire, finally attacked it and won a crushing victory at the Battle of Mühlberg in 1547. He then tried to impose a temporary religious compromise, the Augsburg Interim of 1548, which satisfied almost no one.

The tide turned in 1552. Maurice of Saxony, a Protestant prince who had fought for Charles, changed sides and allied with Henry II of France. The princes’ revolt drove the emperor out of Innsbruck. The Peace of Passau in August 1552 promised a lasting settlement at a future diet, and that diet opened in Augsburg in February 1555.

The negotiations

Charles V refused to take part personally in a settlement that accepted heresy as permanent. He left the negotiations to his brother Ferdinand, King of the Romans, who had governed the Austrian lands for decades and wanted peace in the Empire to face the Ottoman threat.

Maurice of Saxony had died in battle in 1553, and his brother Augustus led the Lutheran princes. After months of bargaining, the Recess of the Diet, the formal record of its decisions, was published on 25 September 1555. Charles signalled his wish to abdicate shortly afterwards.

The discussions were long and difficult. Catholic princes, led by the ecclesiastical electors of Mainz, Trier and Cologne, wanted to protect the remaining bishoprics and abbeys, many of which were also territorial states. Lutheran princes wanted their faith recognised permanently, not merely tolerated until a general council of the Church could settle matters. The final text declared the peace to be lasting, even if the religious split was never healed, which was a major concession by the Catholic side.

One reason for compromise was fear of renewed war. Germany had suffered from the Schmalkaldic War and from the violent campaigns of Margrave Albert Alcibiades of Brandenburg-Kulmbach, who had ravaged Franconia in 1552–1554. Princes of both faiths wanted to restore order and protect their own authority.

The terms

The settlement had several key elements:

• Two lawful faiths: Catholicism and the Lutheran faith of the Augsburg Confession of 1530 were both recognised. No other Protestant group, including Calvinists and Anabaptists, was protected.
• The ruler’s choice: Secular princes and other immediate lords of the Empire could choose either faith for their territory and require their subjects to follow it.
• Right to emigrate: Subjects who would not conform could sell their property and leave, a right known as ius emigrandi. For its time this was a notable concession.
• Imperial cities: In free cities where both faiths were already practised, both were to continue.
• Church lands: Protestants kept church property they had taken before the Peace of Passau in 1552.
• The ecclesiastical reservation: If a Catholic prince-bishop or abbot became Lutheran, he had to give up his office and lands, so that the territory remained Catholic. Protestants never accepted this clause, which Ferdinand inserted on his own authority.

In a separate declaration, the Declaratio Ferdinandea, Ferdinand promised that Lutheran knights and towns already living under Catholic prince-bishops would not be forced to convert. It was not included in the official text, and Catholic rulers later refused to recognise it.

Myths and facts

Myth: the Peace of Augsburg granted religious freedom. It did not. It gave freedom of choice to rulers, not to ordinary people, whose only option if they disagreed was to emigrate.

Myth: the treaty contained the words cuius regio, eius religio. The phrase is a later summary by lawyers. The treaty itself is a long legal document written in German.

Key people

Ferdinand I, Charles V’s younger brother, made the compromise and became emperor himself when Charles’s abdication took effect in 1558.

Charles V had spent his reign trying to preserve one Catholic church in the Empire. Augsburg marked the failure of that hope, and in October 1555 he began handing over his crowns, as described in the abdication of Charles V.

Augustus of Saxony led the Lutheran side and became one of the most important defenders of the settlement in the following decades.

Consequences

The Peace brought the first religious wars in Germany to an end and gave the Empire decades of relative calm. Lutheran churches developed under the protection of their princes, who often became heads of their territorial churches. Religious unity now existed within territories rather than across the Empire as a whole.

Its weaknesses soon showed. From the 1560s Calvinism spread into Germany, most importantly when Elector Frederick III of the Palatinate adopted it. Calvinist princes claimed protection under the Augsburg Confession, which Catholics and many Lutherans denied.

Disputes over the ecclesiastical reservation also grew. The Cologne War of 1583–1588 broke out when the Archbishop of Cologne converted to Protestantism and tried to keep his lands. By 1608–1609 rival Protestant and Catholic alliances had formed, and in 1618 the conflict in Bohemia became the Thirty Years’ War.

Legacy

The Peace of Westphalia of 1648 finally repaired the Augsburg settlement. It extended recognition to Calvinists and fixed 1624 as the reference year for deciding which church owned what property.

The Peace of Augsburg is often seen as an early step towards religious coexistence in Europe, though not towards individual freedom of conscience. It tolerated two churches, not individuals, and tied faith to political power.

In practice the settlement encouraged what historians call confessionalisation. Rulers drew up church ordinances, appointed superintendents, held visitations of parishes and founded schools and universities to train clergy in the correct doctrine. Lutheran Saxony and Württemberg and Catholic Bavaria all became models of this close alliance between church and state. Religious identity increasingly followed territorial borders, a pattern still visible in the map of Catholic and Protestant regions in modern Germany. Historians stress that the famous phrase cuius regio, eius religio was coined by later jurists, usually credited to the lawyer Joachim Stephani around 1600, and does not appear in the treaty.

Timeline

• 1530, June: Lutheran princes present the Augsburg Confession to Charles V.
• 1531, February: The Schmalkaldic League is formed.
• 1547, 24 April: Charles V defeats the League at Mühlberg.
• 1548, May: The Augsburg Interim is proclaimed.
• 1552, August: The Peace of Passau ends the princes’ revolt.
• 1555, February: The Imperial Diet opens at Augsburg.
• 1555, 25 September: The Peace of Augsburg is proclaimed.
• 1618, May: The Defenestration of Prague begins the Thirty Years’ War.
• 1648, 24 October: The Peace of Westphalia revises the settlement.

Why it matters

The Peace of Augsburg accepted, for the first time in law, that Western Christendom was permanently divided. By letting rulers decide their subjects’ faith, it shaped the religious map of Germany for centuries.