Site Loader

In this lesson we explore the Thirty Years’ War and the subsequent Peace of Westphalia. The continental conflict arose out of political and religious issues in the Holy Roman Empire and Europe as a whole, and its conclusion in 1648 changed the face of European politics.

Thirty Years’ War

In the twenty-first century, we take religious freedom for granted: if you don’t like the church you attended last Sunday, try the one across the street. However, if you had lived four hundred years ago, choosing a church was such an important decision that making the wrong choice could cost you your life! From 1618 to 1648, a series of conflicts was fought between Roman Catholic and Protestant states, in part to answer the question of what churches European Christians were allowed to attend. These conflicts are known as the Thirty Years’ War.


During the sixteenth century, Martin Luther’s Protestant Reformation caused Christianity to splinter into numerous sects and subsects. In the Holy Roman Empire, where the Emperor remained a staunch Catholic, members of these sects often had to fight to defend their rights to worship or emigrate to states with princes or monarchs sympathetic to Protestantism.

Best services for writing your paper according to Trustpilot

Premium Partner
From $18.00 per page
4,8 / 5
Writers Experience
Recommended Service
From $13.90 per page
4,6 / 5
Writers Experience
From $20.00 per page
4,5 / 5
Writers Experience
* All Partners were chosen among 50+ writing services by our Customer Satisfaction Team

Conflict between the Emperor and an alliance of German princes – named the Schmalkaldic League – that preferred Lutheranism was settled with the 1555 Peace of Augsburg, in which the Emperor Charles V agreed to allow the princes of each state within the Holy Roman Empire to choose either Catholicism or Lutheranism as the religion of their state.While this measure stopped the internecine struggle for a time, new issues created new problems. As the preacher John Calvin‘s more radical Protestant beliefs gained footing among Europeans during the middle of the sixteenth century, Calvinists began to clamor for the same recognition and acceptance that Lutheran rulers and subjects had achieved with the Peace of Augsburg.

Bohemian Revolt

These tensions came to a head in 1618 in the Germanic state of Bohemia.

King Matthias of Bohemia, who was also Holy Roman Emperor, had no legitimate heirs and in 1617 named the Archduke of Austria, Ferdinand, heir to the Bohemian throne and likewise put him in line to become Holy Roman Emperor. This alarmed the primarily Calvinist population of Bohemia as Ferdinand was an ardent Catholic. In 1618 the Calvinists revolted, famously by first throwing some of Ferdinand’s Catholic advisers out a church window in Prague, an event which became known as the Defenestration of Prague. The Calvinist rebels in Bohemia appealed to the other Protestant states in the Holy Roman Empire for help in throwing off Catholic rule, but their efforts and those of the few allies they found failed; the Bohemians were defeated decisively by Ferdinand – now Holy Roman Emperor Ferdinand II – in 1620 at the Battle of White Mountain. As a result, Catholicism was forced upon Bohemia, and the Protestant king the Bohemians had attempted to install, Frederick V, was exiled from the Holy Roman Empire.

Denmark Invades Holy Roman Empire

Though the Bohemians and their Protestant allies were defeated, fighting began again in 1625 with Denmark’s invasion of the Holy Roman Empire on behalf of the Protestant state of Saxony, which the Danish King Christian IV feared might fall to the Catholic states that encircled it. Christian’s invasion proved foolish, and Emperor Ferdinand employed the Bohemian nobleman and brilliant general Albrecht von Wallenstein to repulse the invaders.

The Danes were defeated several times in Germany and in their own territory and retreated to the Danish islands where Wallenstein, who was without a fleet, could not reach the Danish forces. In 1629, Christian IV and Ferdinand II signed the Treaty of L;beck, which returned previously Danish lands to Denmark in return for a pledge that Denmark would no longer interfere in the affairs of the Empire.

Sweden and France Enter the Fray

At this point, the Thirty Years’ War gained a new political dimension: with the consolidation of power in the Holy Roman Empire by the Emperor, Ferdinand II, France worried about being surrounded, as the Hapsburg family had members installed as both the King of Spain and the Holy Roman Emperor. Meanwhile, Protestant Sweden worried about the growing Catholic forces of the Holy Roman Emperor and what that would mean for Swedish control of the Baltic Sea. As a result, Sweden landed troops in Pomerania in 1630 and France and Sweden signed an alliance – despite France being a Catholic country – to aid the Protestant German states.

The Swedes scored several victories in the northern and central parts of the Empire, led by their King Gustavus Adolphus, until he died in battle in 1632. After his death, the imperial Catholic forces began to claw back lost territory and in 1635 concluded a peace with the Protestant states of the Holy Roman Empire. The 1635 Treaty of Prague stated that princes of the Holy Roman Empire were not allowed to make alliances and treaties with outside sovereign states and merged the armies of each state within the Holy Roman Empire into one imperial army.The Treaty of Prague angered the French, who quickly realized the Treaty strengthened Hapsburg control over the entirety of the Holy Roman Empire; it was the exact antithesis of the stated French goals for entering the war. As a result, France entered the war directly, declaring war on the Holy Roman Empire in 1636 and on the other Hapsburg-controlled state, Spain, in 1635.

The Swedes and several Protestant Germanic states joined the French in continuing the war. Despite early Spanish successes, French and Swedish forces were largely successful in military efforts over the next decade.

Peace of Westphalia

In the face of French and Swedish victories in the north and west, Ferdinand III (who had taken the imperial throne after his father’s death in 1637) sought to negotiate an end to the protracted conflict.

Over the last several years a series of treaties and ceasefires were signed between France, Spain, Sweden, the Holy Roman Empire, and various Germanic states. These collective agreements became known as the Peace of Westphalia.Pragmatically, the Peace achieved several things. Some territory changed hands, as France was granted parts of Alsace and Sweden gained part of Pomerania.

Calvinists were granted the same degree of toleration in the Holy Roman Empire that Lutherans had been afforded since 1555, and the states of the Holy Roman Empire were granted a greater degree of sovereignty from the imperial throne than they had previously held; indeed, any illusions Emperor Ferdinand III had of retaining strong authority over all of the Holy Roman Empire’s provinces and maintaining the Empire as a solely Catholic entity were shattered. In turn, the Peace of Westphalia, through destroying imperial authority, isolated Hapsburg Spain and primed France to become the preeminent power of continental Europe under King Louis XIV.


In closing, the Thirty Years’ War was not one war, per se, but a series of conflicts fought between the great continental powers of seventeenth-century Europe. Though the conflict was originally instigated to defend the religious freedoms of Calvinists and Protestants in the Holy Roman Empire, European politics soon became a driving force behind the war’s main actors. The war’s results and the terms of the Peace of Westphalia shaped the nature of European politics and power for decades following.

Learning Outcomes

When this lesson is completed, you should be able to:

  • Understand the causes of the Thirty Year’s War
  • Identify the primary nations in play during the war
  • Recall the results of the Peace of Westphalia

Post Author: admin


I'm Eric!

Would you like to get a custom essay? How about receiving a customized one?

Check it out