The Reformation and Wars of Religion

David J. B. Trim May/June 2010

This article is part two in a four part series.

Starting in the 1520s international relations between the rising European states were dominated by conflicts that were primarily or significantly religious in character: wars in central and southern Europe, between Christians and Muslims; and, in central and northwestern Europe, confessional wars, the fruit of the Reformation. The division between Protestant and Catholic caused or intensified numerous conflicts, resulting in some of the longest lasting, bloodiest, and most bitterly contested and destructive wars in history. This second in a five-part series of articles on Europe’s wars of religion tells the story of the confessional wars in sixteenth- and seventeenth-century Christendom.1 The next article will consider what conclusions and lessons can be drawn from the narrative that follows. The fourth article will briefly recount the history of the sixteenth- and seventeenth-century wars against Islam, before the last article in the series examines the end of the era of wars of religion.

Germany, 1524–1535

In 1524–1525 peasants rose in revolt across southern and western Germany, inflamed by the version of the Lutheran Reformation preached by Thomas Müntzer, who had been one of Martin Luther’s early followers but had been banished for his radicalism and militancy. Some of the peasants’ demands were socioeconomic, but all derived from the belief that the whole of human society, rather than just theology and the church, ought to be remade in accordance with biblical principles and the law of God. In a sense, the Peasants’ War (as the resulting conflict was called) was the first of the post-Reformation wars of religion. Yet it was unusual, in that Luther condemned the peasants and the war ended with the slaughter of peasants by both Lutheran and Catholic armies.

There was another outbreak of radical, lower-order Protestant violence in Müntzer in 1534–1535, in which the ruling bishop was deposed by Anabaptists, who then established their own “kingdom,” led by Jan of Leiden, who proclaimed himself the messiah. He maintained his authority by imprisoning and killing those who doubted him, but was able to command enough support from the supposedly pacifist Anabaptists to keep the bishop and Catholic armies at bay for 18 months. On the city’s fall he and most of his followers were put to the sword.

Thereafter, however, in religious civil wars there was fighting within and among both the aristocracy and the peasants, rather than nobles fighting commoners. Societies were polarized along confessional lines.


In Zurich, a constituent canton of the Swiss Confed­eration, the burgomaster and city council had imposed a reorganization of the church in 1523, which was inspired and its implementation led by Huldrych Zwingli. The emergence of what became known as Protestantism in Zurich split the Swiss Confederation, however, and in 1529 and 1531 the Zwinglian and Catholic cantons clashed in the first and second wars of Kappel. Zurich had the worst of the Second War of Kappel, in which Zwingli, the second great leader of the Reformation, was killed in battle; but later in the century the survival of the Reformation in the Protestant cantons of Switzerland was ensured by the strength of the armies of Bern and Zurich. The cities used this military power to impose Protestantism on, or preserve it in, other cities and cantons, notably Geneva, Lausanne, the Pays de Vaud, and Mulhouse.

Germany 1546–1555: The Schmalkaldic Wars

Meanwhile in Germany, Lutheran princes and cities established a defensive alliance, the League of Schmalkalden, in 1531 to protect individual territories from attack by the emperor, Charles V. But in practice the league aided Lutherans in other states, thereby helping to spread Lutheranism by force throughout northern Germany. Eventually, in 1546, open war between the emperor and the league broke out. The Schmalkaldic War is usually said to have lasted only until 1547, when on April 24 the emperor won a celebrated victory at the Battle of Mühlberg, which he hoped would be a springboard to end religious conflict in the empire. Lutheranism was, however, now too strongly entrenched for one victory to make a decisive difference; hostilities continued in Germany until 1552. The confessional nature of this war is clouded, because Maurice of Saxony and other Lutheran princes fought for the emperor, and the political relationship of the princes and free cities of the empire vis-à-vis the emperor was one of the issues at stake. Yet there is no question that confessional divisions were a major factor both in causing and in perpetuating the wars of the 1540s and 1550s.

In the end an uneasy peace returned to the empire thanks to a compromise and peace treaty concluded at Augsburg in 1555. It agreed a principle famously summed up in the Latin tag cuius regio, eius religio (“whose reign, that religion,” i.e., “in the prince’s land, the prince’s religion”). This provided that the confessional affiliation of each territory in the empire, whether princely state or free city, was to be determined by its ruler: usually the prince, but in city-states, the ruling council. The prince would choose his confession, Protestant or Catholic, and that would set the official religion for all his subjects. Once a ruler’s religious views had been decided and announced, those of his subjects whose allegiance lay with a different confession had a limited time period in which they had to either migrate to a state whose official religion was in line with their own, or conform—if they failed to do either, then they could be subjected to persecution, imprisonment, fines, or execution, and no neighboring state would intervene.

This doctrine of ecclesiastical territoriality could not be more at odds with notions of religious freedom—all confessions, Catholics and Protestants, conceded the right to impose the faith of the government upon the governed. Probably neither Protestant nor Catholic expected the Augsburg compromise to last, but in fact it was not until the outbreak of the Thirty Years’ War in 1618 that it was challenged; and once the war ended, with the Peace of Westphalia (1648), the doctrine was largely (albeit, as we shall see, not totally) restored.

Rivalz, Antoine (1667-1735)
The expulsion of the Huguenots from Toulouse after the siege of the town by troops of the Prince de Conde, 1562.

The Reformed Churches—Militant Protestantism

A new strain of Protestantism was to make the European wars of religion more widespread and more bitterly fought. Calvinism emerged in Geneva in the 1540s, preserved from its Catholic neighbors chiefly by Bern’s military strength. Genevan Calvinism fused with the reformation of Zurich and northern Switzerland, which had been led by Zwingli and Heinrich Bullinger, to produce what became known as Reformed (with a capital R) Protestantism. It has generally been referred to simply as “Calvinism,” and its adherents (called Puritans in England and North America, Huguenots in France, and Presbyterians in Scotland) simply “Calvinists.” However, recent research by historians has revealed that this underestimates other Swiss influences on Reformed thought and practice, especially that of Zwingli and Bullinger, though on the other hand, the recent scholarly tendency to prefer “Reformed” over “Calvinist” fails to do justice to Calvin’s role in taking the ideas and practices of other Swiss Reformers and shaping (or reshaping) them into a cohesive, intellectually powerful, appealing, and militant whole.

Reformed theology and ecclesiology were such that Calvinism was in some ways a confession made for war. Many of its adherents were remarkably militant, and its organizational structure itself led to militarization. The distinctively Reformed doctrine of predestination and the Reformed version of the doctrine of the church meant that wherever there were members of God’s elect, predestined to salvation, there also must be the Reformed Church, an institution and organization. Unlike Lutherans, therefore, the Reformed could have no truck with the ecclesiastical territoriality that had ended religious war in Germany.

For Calvinists liberty of conscience had to be matched by liberty of worship. They also, collectively, had a formidable sense of group identity that transcended earthly ethnic and national identities. One branch of the Reformed Church in danger was likely to receive financial and military help from the other branches, thus internationalizing wars in which the Reformed were engaged.

In addition, even more than other Protestants, the Reformed viewed the world through an apocalyptic lens. The Papacy did not merely have the characteristics of antichrist; it was not merely a type of antichrist: it really was the antichrist. Further, like most exegetes of Daniel and Revelation, they were postmillennialists—that is, they believed Christ’s second coming would follow, rather than precede, the millennium, which might be inaugurated partly by the actions of God’s elect on earth. This, combined with other doctrines, helped to produce an extraordinary boldness and defiance in the face of adversity—for God could turn even the darkest situation into triumph, and because those whom the Reformed were fighting were enemies in a cosmic, not merely a human, sense.

Finally, Reformed ecclesiology was also distinctive, and was based around a pyramidal, partly representative organizational structure, which could be easily mobilized. Local churches were readily turned into companies, with the consistory (the quintessentially Reformed body governing each local church) taking a leading role; the equally Calvinist regional authorities—synods, colloquies, or classes—then helped turn the companies of their region into regiments.

All this must be borne in mind when considering the extraordinary extent, duration, bitterness, and bloodiness of the wars that raged across France, the Low Countries, the British Isles, and Germany in the 90 years after 1560.

The French Wars of Religion, 1562–1629

Disputes about the place of an organized and powerful Reformed minority (the Huguenots) in what was a Catholic state resulted in France being racked by nearly 40 years of confessional conflict in the late sixteenth century. There were nine nationwide civil wars, the guerres de religion, which incorporated 21 years of formal warfare between March 1562 and April 1598. Informal violence was endemic even in some years of nominal peace—in the Saint Bartholomew’s Day Massacre in Paris in August 1572, some 3,000 Huguenots were slaughtered, and probably another 7,000 were slain in a dozen massacres that followed in provincial cities across France.2

In the seventeenth century, further localized but serious wars followed periodically from 1612 to 1629. English, German, Scottish, Dutch, and Swiss troops aided the Huguenots; Spanish, Italian, German, and Swiss troops aided the Catholics.

The Dutch navy battles a Spanish fleet at Gibraltar. Painting by Corelis Claesz van Wieringen.

The Dutch Revolt, 1567–1648

In the Netherlands an unsuccessful revolt in 1567–1568 against the plans of the Spanish ruler, Philip II, for governmental and ecclesiastical reform gave way to guerrilla warfare on land and sea by Calvinist diehards, before a further revolt in the spring of 1572 triggered 37 years of constant warfare, followed by a 12-year truce with Spain, followed by renewed hostilities from 1621 to 1648: what the Dutch, slightly misleadingly, later called the Eighty Years’ War. Not all the Dutch rebels against Spain were Calvinists—they included Lutherans, Anabaptists, and members of smaller radical Protestant sects, such as the Family of Love, as well as Jews and some Roman Catholics. The Revolt of the Netherlands had political and economic, as well as confessional, objectives.

However, the Reformed, by their willingness to defy the military logic of their situation in the 1570s, provided the motor for the revolt; and it was religion that made the war last so long. In the first 40 years both sides were ultimately willing to compromise on everything that divided them except for religion. The only religious liberty Spain would concede was a period of grace in which recalcitrant Protestants could make arrangements to emigrate. Even those Netherlanders who were not fighting for religion would not doom their neighbors to such a fate. By the seventeenth century the Reformed Church was effectively the state church of the Netherlands; the Reformed agenda drove national policy. This meant that foreign Reformed communities aided their fellow Calvinists. At various times England, Scotland, France, and the Protestant German princes were open allies of the United Provinces of the Netherlands, and many English, Scottish, and Huguenot soldiers served the Dutch cause as volunteers, even when their governments were formally at peace with Spain.

The Thirty Years’ War, 1618–1648

The Thirty Years’ War was triggered by Calvinists. Bohemian Calvinists resisted attempts by Ferdinand II, archduke of Austria, Holy Roman Emperor, and elector of Bohemia, to restrict religious freedoms (already limited!) dating back to the Hussite wars of the 1430s (discussed in the previous article in this series). Their unwillingness to accept religious persecution led the Bohemians to declare Ferdinand deposed; they invited the elector palatine, perhaps the most important Calvinist German prince, to take the Bohemian throne from its Habsburg incumbent. However, the war involved more than Calvinist-Catholic religious differences; the peace established at Augsburg had become increasingly uneasy.

By 1618 Ferdinand II, who had been educated by Jesuits, seems genuinely to have believed that by force of arms he could overturn the Lutheran Reformation. It must be added that the reputation of Jesuits in Protestant historiography is mostly undeserved—but not wholly. They were far more earnest and sincere missionaries and preachers of Jesus than they were Machiavellian conspirators or “storm troopers of the Counter-Reformation”—yet they could be unyielding and aggressive opponents of Protestantism. It is remarkable that both Sebastian I of Portugal and Emperor Ferdinand II were educated by Jesuits and both as adults firmly opposed any form of compromise with enemies of the faith, whose influence they sought to overturn by force of arms. Sebastian’s 1578 “crusade” against Muslims in Morocco (discussed in the next article in this series) ruined Portugal; Ferdinand’s policies brought about the Thirty Years’ War—“Europe’s tragedy,” as a recent authoritative history calls it.3

Ferdinand provoked the Bohemian Revolt by reversing policies of limited toleration, thus helping to spread and to prolong the Thirty Years’ War. First, he vindictively conquered the elector palatine’s Rhineland principality, then annexed the imperial electorship that went with it, thus changing the balance of power within the empire. Second, in 1629 he issued the Edict of Restitution, which aimed to turn the religious clock back to 1552—a date carefully chosen, instead of 1555 (when the Peace of Augsburg was agreed), because it was the height of Charles V’s successes in the Schmalkaldic Wars. Protestants had been divided, but the danger posed by Ferdinand’s ambitions was so obvious that gradually the war spread: it became general across Germany in the 1620s, then encompassed the Lutheran kingdoms of Denmark-Norway and Sweden, and subsumed the second half of the Eighty Years’ War between Spain and the Dutch Republic.

The religious character of the Thirty Years’ War eventually was diminished, particularly by the entrance of Catholic France on the Protestant side in the early 1630s. The result was that for much of the second half of the war it was as much about rivalry between France and the Habsburg rulers of Austria and Spain, and about the politics of the empire, as about the Protestant-Catholic divide. However, the war was both started and prolonged by confessional rivalry; and confessional hatred helped make it so destructive of both human life and property that it was probably the greatest disaster to affect Europe between the Black Death and the First World War.

In the end, the Peace of Westphalia, which ended the war in 1648, endorsed the cuius regio, eius religio principle of Augsburg and effectively tried to apply it not only to the empire but also to international relations in general. The rights of some religious minorities were recognized and protected, which was a major step forward; but on the whole, the sovereigns of Europe agreed that the internal affairs of other states were the business of only the sovereigns of those states, who were permitted to persecute dissenters and dissidents as they saw fit.

The British Isles and Europe,1560–1651

In Scotland, Presbyterian determination to resist Catholic oppression resulted in a civil war in 1560, and a coup that overthrew the sovereign in the late 1560s. Three English invasions followed, initially to ensure liberty of conscience and worship for Protestants, later to maintain a Protestant government—all this in just 14 years, from 1560 through 1573.

After intervening in the affairs of her Scottish neighbor, Elizabeth I of England fought Catholic Spain from 1585 to 1603. The Spanish attempt to invade England in 1588, with the great fleet known as the Spanish Armada, is the best-known event of this war, but it lasted 19 years and was bitterly fought: English troops saw combat against Spanish forces in the Netherlands, France, Spain, Portugal, Ireland, the Caribbean, and South America. The three British kingdoms were united by the Stuarts, after the Tudor dynasty died out with Elizabeth in 1603; her successor, James I, made peace with Spain in 1604. But his son, Charles I, waged war on Spain again in 1625. The British monarchy then stayed out of the Thirty Years’ War, but royal religious policy provoked resentment among the Reformed of both England and Scotland, and among Ireland’s majority Catholic population.

Confessional divisions eventually helped to spawn the British civil wars that began in 1640 and lasted from 1641 to 1651, wreaking destruction across the whole of the British Isles. Massacres and atrocities were commonplace in Ireland, but were not unknown in England, Wales, and Scotland. The wars ended with the so-called Puritan Revolution, which (briefly) abolished the monarchy and established a British republic, under the leadership of the fervent Calvinist Oliver Cromwell.4

Thus, from the 1520s until approximately 1650 the greatest nations in Christendom—France, Spain, Portugal, Austria, Sweden, the Dutch Republic, and Britain—were all caught up in wars that were, either in part or in whole, the result of the divisions engendered by the Reformation. The obvious questions are why did the wars last so long and why were they so bitterly contested? These questions will be considered in the next article in this series.

Professor D.J.B. Trim is a historian and member of the Cromwell Society. He writes from London, England. With many years of experience teaching college history, he is currently associated with the University of Reading.

  1. This article draws substantially from D.J.B. Trim, “Conflict, Religion, and Ideology,” in Trim and F. Tallett, eds, European Warfare, 1350–1750 (New York and Cambridge: Cambridge University Press, 2010), chap. 13.
  2. A summary overview has appeared in an earlier article: D.J.B. Trim, “Tumults, Riots, and Seditions: Persecution and Violence in France During the Wars of Religion,” Liberty, May/June 2007, pp. 16-21.
  3. Peter H. Wilson, Europe’s Tragedy: A History of the Thirty Years’ War (New York: Penguin, 2009)—the best history in English.
  4. Discussed in an earlier short series: see D.J.B. Trim, “Oliver Cromwell: The Intolerant Inheritance of America’s Religious Extreme,” part 1, Liberty, Nov./Dec. 2006, pp. 12-15, 22, 23; “A Moral Vision: Oliver Cromwell and the Transformed Christian Nation . . . ,” part 2, Liberty, Jan./Feb. 2007, pp. 8-13, 26, 27.

Article Author: David J. B. Trim