The Thirty Years’ War

The Thirty Years’ War was a series of connected wars fought between 1618 and 1648, mainly in the Holy Roman Empire — a large, loosely united political body covering today’s Germany, Austria, the Czech Republic and neighbouring regions, headed by an elected emperor from the Habsburg family.

It began as a revolt of the Protestant nobles of Bohemia against their Habsburg king. Over the years, it drew in Spain, Denmark, Sweden, France and many German princes. Religion — the division between Catholics and different kinds of Protestants — mattered a great deal, but so did questions about the emperor’s power, princes’ rights and the rivalry between the Habsburgs and France.

It was one of the most destructive wars in European history before the twentieth century. It ended with the Peace of Westphalia in 1648, a set of treaties that settled religious rights in the Empire, recognised Swiss and Dutch independence, and gave land to Sweden and France.

A century earlier, the Protestant Reformation begun by Martin Luther had split the Empire. The Peace of Augsburg of 1555 let each Lutheran or Catholic prince choose the religion of his territory. But it did not include Calvinists, whose numbers grew, and it left disputes over church lands unresolved. By 1608–1609 rival alliances had formed: the Protestant Union and the Catholic League.

In Bohemia, the nobles had won guarantees of religious freedom in 1609. When the strongly Catholic Ferdinand of Styria became their king-designate, they feared those rights would be taken away. On 23 May 1618 a group of Protestant nobles threw two imperial governors and a secretary out of a window of Prague Castle. All three survived — Catholics said angels saved them, Protestants said they landed on a dung heap — but the rebellion had begun.

The Bohemian estates deposed Ferdinand and in 1619 chose a Calvinist prince, Frederick V, Elector Palatine, as their king. Ferdinand, who had just been elected emperor as Ferdinand II, was determined to win back Bohemia. A local revolt was about to become a war involving the whole Empire and its neighbours.

On one side stood the Austrian Habsburg emperors, the Catholic League led by Duke (later Elector) Maximilian of Bavaria, and the Spanish Habsburgs, who were also fighting the Dutch Republic. On the other side, at different times, were Bohemian and Palatine rebels, King Christian IV of Denmark, King Gustavus Adolphus of Sweden and his successors, and Catholic France under Cardinal Richelieu, which supported Protestant allies because it feared Habsburg power more than it disliked Protestantism.

Armies were large for their time and made up mostly of hired soldiers from all over Europe. Rulers rarely had enough money to pay them. Commanders such as Albrecht von Wallenstein developed a system of “contributions”: forcing towns and regions to supply money, food and quarters to the troops. This made armies possible but spread the burden — and the violence — across the countryside.

Armies were followed by large trains of women, children, servants and traders who cooked, nursed, sold goods and scavenged. Together with the soldiers, they carried diseases such as plague and typhus from region to region.

Imperial and Catholic League forces crushed the Bohemian rebels at the Battle of White Mountain near Prague on 8 November 1620. Frederick V fled and became mocked as the “Winter King”. In 1621 leaders of the revolt were publicly executed in Prague. Protestant worship was gradually banned in Bohemia, many Protestant nobles lost their lands, and tens of thousands of people emigrated, among them the educator John Amos Comenius.

The war moved to Frederick’s home, the Palatinate on the Rhine, which was occupied by Spanish and Bavarian troops. Its famous library at Heidelberg was taken to Rome as a gift for the pope. Frederick’s electoral title was transferred to Maximilian of Bavaria in 1623, which alarmed Protestant princes.

In 1625 Christian IV of Denmark intervened but was defeated by Tilly at Lutter in 1626. Wallenstein raised a huge imperial army and pushed as far as the Baltic coast. At the height of his success, Ferdinand II issued the Edict of Restitution (1629), ordering the return to the Catholic Church of church lands taken by Protestants since 1552. This frightened even Lutheran princes who had stayed loyal, and helped prolong the war.

In 1630 Gustavus Adolphus of Sweden landed in Pomerania, partly to protect Protestants and partly to secure Swedish power around the Baltic, with French subsidies from 1631. In May 1631 Tilly’s army stormed the Protestant city of Magdeburg; fire and massacre destroyed most of the city and killed a large part of its population, often estimated at around 20,000 people. News of the sack spread across Europe in pamphlets and prints.

Gustavus won a great victory at Breitenfeld in September 1631 and marched deep into southern Germany. He was killed at the Battle of Lützen in November 1632, though his army won. Wallenstein, suspected of secret negotiations, was assassinated by his own officers in 1634 with the emperor’s approval. After an imperial-Spanish victory at Nördlingen in 1634, most German Protestant princes made peace with the emperor in the Peace of Prague (1635).

The war did not end, because France now entered it directly, declaring war on Spain in 1635 and fighting alongside Sweden. For thirteen more years armies marched back and forth across a devastated Empire. The French defeated the Spanish at Rocroi in 1643, and Swedish and French armies won major battles in the 1640s. Peace negotiations began at Münster and Osnabrück in the mid-1640s while fighting went on; Swedish troops were besieging Prague when news of the peace arrived in 1648. The war between France and Spain continued until 1659.

The peace was negotiated by delegations from across Europe in two Westphalian towns: Catholic powers mainly at Münster, Protestant powers mainly at Osnabrück. Earlier in 1648 Spain made a separate peace with the Dutch Republic, recognising its independence. The treaties with Sweden and France were signed on 24 October 1648.

In the Empire, Calvinism was recognised alongside Lutheranism and Catholicism. The year 1624 was fixed as the “normative year”: the religious situation of that date would largely determine who kept which churches and properties. Princes were confirmed in wide powers over their territories, including the right to make alliances as long as these were not directed against the emperor or Empire. A new, eighth electorate was created for Frederick V’s son, while Bavaria kept the one it had gained.

Sweden gained Western Pomerania and other territories on the North Sea and Baltic coasts, making it a great power. France had its control of Metz, Toul and Verdun confirmed and gained rights in Alsace. The independence of the Swiss Confederation from the Empire was also acknowledged.

Modern estimates of total deaths are usually given as about 4.5 to 8 million people, though all figures are uncertain because records were patchy and people moved to escape danger. Most victims were civilians, and most died not in battle but of epidemics and hunger made worse by the war, plundering, poor harvests and refugees crowding into towns.

The loss of population varied greatly from place to place. Some regions, such as parts of Pomerania, Württemberg and the Palatinate, may have lost more than half their inhabitants; others, especially in the north-west, suffered much less. Historians today prefer these regional pictures to a single dramatic number for “Germany”.

Contemporary accounts describe looting, torture to reveal hidden money, rape, kidnapping and the burning of villages. Such descriptions come partly from propaganda and literature, but they are also confirmed by local records, diaries and parish registers. At the same time, some people survived by fleeing, bargaining with soldiers or joining the armies themselves.

The war also changed where people lived. Walled cities filled with refugees from the countryside, which helped epidemics spread; later, abandoned farms were resettled by migrants from Switzerland, Austria and other less damaged regions. Women faced particular dangers from soldiers, but they also kept farms and workshops going, negotiated with occupying troops, and travelled with the armies as wives, cooks, sutlers and nurses. Religious minorities were uprooted as rulers changed and enforced their own confession, and Jewish communities, though sometimes protected in return for payments, were exposed to extortion and violence from all sides.

In the short term, the war left many German territories impoverished, depopulated and in debt. Recovery took decades, and in some places the population did not return to pre-war levels until the eighteenth century. Rulers used the post-war period to rebuild administration, taxation and, in some states such as Brandenburg-Prussia, permanent armies.

Politically, the Empire survived, but with a balance between the emperor and the princes that lasted until 1806. The Austrian Habsburgs increasingly focused on their own hereditary lands, including a re-Catholicised Bohemia. France and Sweden emerged as the leading powers of the mid-seventeenth century, while Spain’s decline continued.

Religiously, the peace did not end confessional hostility, but it made large-scale religious war within the Empire far less likely by moving disputes into courts and legal procedures. The Peace of Westphalia is often said to have founded the modern system of sovereign states; many historians now think this claim is exaggerated (see the debates below).

In Germany, the war became a symbol of national catastrophe. Hans Jakob Christoffel von Grimmelshausen’s novel Simplicius Simplicissimus (1668) told it through the eyes of a naive boy. Friedrich Schiller wrote a history of the war and the Wallenstein trilogy of plays in the 1790s. In 1939 Bertolt Brecht used the war as the setting for Mother Courage and Her Children, a warning about profiting from war. Nineteenth-century nationalists often blamed foreign powers for Germany’s long weakness, and the war was sometimes compared with the destruction of the World Wars.

In Sweden, Gustavus Adolphus is remembered as a great king and defender of Protestantism, and 6 November, the day of his death at Lützen, is marked in Sweden and Finland. In the Czech lands, the defeat at White Mountain was long remembered in nationalist writing as the start of a “dark age” of Habsburg rule, re-Catholicisation and German-speaking dominance, although modern historians paint a more complex picture of the Baroque era.

In France, the war is often seen through Richelieu’s policy of reason of state, placing French interests above religious solidarity. In the Netherlands, 1648 is remembered as the recognition of Dutch independence after the Eighty Years’ War. Catholic and Protestant historians once told the war as a struggle of good against evil from their own side; today historians try to present all these perspectives, including those of ordinary soldiers and villagers.

The Thirty Years’ War was the first great European war to be reported widely in print. Pamphlets, illustrated broadsheets and early weekly newspapers spread news and propaganda about events such as the Defenestration and the sack of Magdeburg. Large compilations such as the Theatrum Europaeum collected reports and engravings. These sources show how people learned about the war, but they are often partisan.

Personal documents give ground-level views. The diary of the mercenary Peter Hagendorf, rediscovered in the twentieth century and published in the 1990s, follows a soldier and his family through decades of campaigns. The shoemaker Hans Heberle, near Ulm, recorded how often his village fled to the city. Otto von Guericke, later famous as a scientist, left an account of the destruction of Magdeburg.

Official sources include the texts of treaties such as the Peace of Westphalia, diplomatic correspondence from the Westphalian congress, army and tax records, and parish registers of births, marriages and burials. Demographic historians use such registers carefully, since registers themselves were often interrupted when clergy fled or churches burned.

Was it a religious war? Older histories often described it as the last great war of religion. Peter H. Wilson’s major study Europe’s Tragedy (2009) argues that religion mattered mainly as it shaped political ideas about order and legitimacy, and that the conflict was above all about the constitution of the Empire. Others stress that confessional belief was central for many actors. Most historians now combine religious, constitutional and international explanations.

Was it one war or many? Some scholars, such as S. H. Steinberg in the 1960s, argued that the “Thirty Years’ War” is a later construction covering several separate conflicts, and that the devastation had been exaggerated by later writers. Later demographic research, including regional studies, confirmed very heavy losses in many areas while also showing strong regional variation. Older population estimates by Günther Franz have been widely used but also criticised.

What did Westphalia create? In international relations theory, “Westphalian sovereignty” refers to a system of independent, equal states that do not interfere in each other’s internal affairs. Historians such as Andreas Osiander have argued that this is a “Westphalian myth”: the treaties actually strengthened the Empire’s legal framework, guaranteed religious rights inside territories and gave foreign powers a role as guarantors. Geoffrey Parker has also placed the war in a wider “general crisis” of the seventeenth century linked to climate cooling, revolts and wars around the world.