Peace of Augsburg in the context of "Confessionalization"

The Thirty Years' War, fought primarily in Central Europe between 1618 and 1648, was one of the most destructive conflicts in human history. An estimated 4.5 to 8 million soldiers and civilians died from the effects of battle, famine, or disease, with parts of Germany reporting population declines of over 50%. Related conflicts include the Eighty Years' War, the War of the Mantuan Succession, the Franco-Spanish War, the Torstenson War, the Dutch–Portuguese War, and the Portuguese Restoration War.

Its causes derived from religious conflict within the Holy Roman Empire, sparked by the 16th-century Reformation. The 1555 Peace of Augsburg attempted to resolve this by dividing the Empire into Catholic and Lutheran states, but was later destabilised by the expansion of Protestantism beyond these boundaries. Combined with disagreements over the limits of imperial authority, religion was thus an important factor in starting the war. However, its scope and extent was largely the consequence of external drivers such as the French–Habsburg rivalry and the Dutch Revolt.

Augsburg (UK: /ˈaʊɡzbɜːrɡ/ OWGZ-burg, also US: /ˈɔːɡz-/ AWGZ-; German: [ˈaʊksbʊʁk] ; Swabian German: Ougschburg) is a city in the Bavarian part of Swabia, Germany, around 50 kilometres (31 mi) west of the Bavarian capital Munich. It is a university town and the regional seat of the Regierungsbezirk Swabia with a well-preserved Altstadt (historical city centre). Augsburg is an urban district and home to the institutions of the Landkreis Augsburg. It is the third-largest city in Bavaria (after Munich and Nuremberg), with a population of 304,000 and 885,000 in its metropolitan area.

After Neuss, Trier, Worms, Cologne and Xanten, Augsburg is one of Germany's oldest cities, founded in 15 BC by the Romans as Augusta Vindelicorum and named after the Roman emperor Augustus. It was a Free Imperial City from 1276 to 1803 and the home of the patrician Fugger and Welser families that dominated European banking in the 16th century. According to Behringer, in the sixteenth century it became "the dominant centre of early capitalism", having benefited from being part of the Kaiserliche Reichspost system as "the location of the most important post office within the Holy Roman Empire" and the city's close connection to Maximilian I. The city played a leading role in the Reformation as the site of the 1530 Augsburg Confession and the 1555 Peace of Augsburg. The Fuggerei, the oldest social housing complex in the world, was founded in 1513 by Jakob Fugger.

The German-speaking states of the early modern period (c. 1500–1800) were divided politically and religiously. Religious tensions between the states comprising the Holy Roman Empire had existed during the preceding period of the Late Middle Ages (c. 1250–1500), notably erupting in Bohemia with the Hussite Wars (1419–1434). The defining religious movement of this period, the Reformation, led to unprecedented levels of violence and political upheaval for the region.

Usually considered to have begun with the publication of the Ninety-five Theses (1517) by Martin Luther in the city of Wittenberg (then within the Electorate of Saxony, now located within the modern German state of Saxony-Anhalt), the progression of the Reformation would divide the German states among new religious lines: the north, the east, and many of the major cities—Strasbourg, Frankfurt, and Nuremberg—becoming Protestant while the southern and western regions largely remained Catholic. Compromises and reforms would be made in an effort to promote internal stability within the Holy Roman Empire, importantly with the Peace of Augsburg in 1555, but these efforts would ultimately fall short and culminate in one of the most destructive conflicts the European continent had yet seen, the Thirty Years' War (1618–1648) which ended with the adoption of the incredibly consequential Peace of Westphalia.

Maximilian II (31 July 1527 – 12 October 1576) was Holy Roman Emperor from 1564 until his death in 1576. A member of the Austrian House of Habsburg, he was crowned King of Bohemia in Prague on 14 May 1562 and elected King of Germany (King of the Romans) on 24 November 1562. On 8 September 1563, he was crowned King of Hungary and Croatia in the Hungarian capital Pressburg (Pozsony in Hungarian; now Bratislava, Slovakia). On 25 July 1564, he succeeded his father Ferdinand I as Holy Roman Emperor.

Maximilian's rule was shaped by the confessionalization process after the 1555 Peace of Augsburg. Though a Habsburg and a Catholic, he approached the Lutheran Imperial estates with a view to overcome the denominational schism, which ultimately failed. He also was faced with the ongoing Ottoman–Habsburg wars and rising conflicts with his Spanish Habsburg cousins.

Cuius regio, eius religio (Ecclesiastical Latin: [ˈku.jus ˈre.d͡ʒi.o ˈe.jus reˈli.d͡ʒi.o]) is a Latin phrase which literally means "whose realm, his religion" – meaning that the religion of the ruler was to dictate the religion of those ruled. This legal principle marked a major development in the collective (if not individual) freedom of religion within Western civilization. Before tolerance of individual religious divergences became accepted, most statesmen and political theorists took it for granted that religious diversity was wrong and/or weakened a state – and particularly weakened ecclesiastically transmitted control and monitoring in a state. The principle of "cuius regio" was a compromise in the conflict between this paradigm of statecraft and the emerging trend toward religious pluralism (coexistence within a single territory) developing throughout the German-speaking lands of the Holy Roman Empire. It permitted assortative migration of adherents to two religious groups, Roman Catholic and Lutheran, eliding other confessions.

At the Peace of Augsburg of 1555, which ended a period of armed conflict between Roman Catholic and Protestant forces within the Holy Roman Empire, the rulers of the German-speaking states and the Holy Roman Emperor, Charles V, agreed to accept this principle.

Anti-Protestantism is bias, hatred or distrust against some or all branches of Protestantism and/or its followers, especially when amplified in legal, political, ethic or military measures.

Protestants were not tolerated throughout most of Europe until the Peace of Augsburg of 1555 approved Lutheranism as an alternative for Roman Catholicism as a state religion of various states within the Holy Roman Empire of the German Nation. Calvinism was not recognized until the Peace of Westphalia of 1648. Other states, such as France, made similar agreements in the early stages of the Reformation. Poland–Lithuania had a long history of religious tolerance. However, the tolerance stopped after the Thirty Years' War in Germany, the persecution of Huguenots and the French Wars of Religion in France, the change in power between Protestant and Roman Catholic rulers after the death of Henry VIII of England in England, and the launch of the Counter-Reformation in Italy, Spain, Habsburg Austria and Poland-Lithuania. Anabaptism arose as a part of the Radical Reformation, lacking the support of the state which Lutheranism and Calvinism enjoyed, and thus was persecuted.

The diets of Augsburg were the meetings of the Imperial Diet of the Holy Roman Empire held in the German city of Augsburg. Both an Imperial City and the residence of the Augsburg prince-bishops, the town had hosted the Estates in many such sessions since the 10th century. In 1282, the diet of Augsburg assigned the control of Austria to the House of Habsburg. In the 16th century, twelve of thirty-five imperial diets were held in Augsburg, a result of the close financial relationship between the Augsburg-based banking families such as the Fugger and the reigning Habsburg emperors, particularly Maximilian I and his grandson Charles V. Nevertheless, the meetings of 1518, 1530, 1547/48 and 1555, during the Reformation and the ensuing religious war between the Catholic emperor and the Protestant Schmalkaldic League, are especially noteworthy. With the Peace of Augsburg, the cuius regio, eius religio principle let each prince decide the religion of his subjects and inhabitants who chose not to conform could leave.