The Thirty Years War
Overview
Statewide Dual Credit Modern World History: Unit 3, Lesson 3
The Thirty Years' War (1618-1648) was a devastating European conflict that began as a local religious conflict in Bohemia and eventually involved all of Europe. The war is divided into four phases and is marked by shifting alliances and interventions by foreign powers. Ultimately, the war ended in a stalemate with the Peace of Westphalia, which restated the terms of the Peace of Augsburg from 1555.
Thirty Years’ War adapted from World History Encyclopedia | CC BY-NC-SA
The Thirty Years’ War (1618-1648) was the last major European conflict informed by religious divisions and one of the most devastating in European history resulting in a death toll of approximately 8 million. Beginning as a local conflict in Bohemia, it eventually involved all of Europe, influencing the development of the modern era.
The war is most easily understood by dividing it into four phases:
- Bohemian Revolt (1618-1620)
- Denmark’s Engagement (1625-1629)
- Sweden’s Engagement (1630-1634)
- France’s Engagement (1635-1648)
The Protestant Reformation had encouraged religious dissention and social unrest since 1517 which was addressed by the Peace of Augsburg in 1555, establishing the policy of cuius regio, eius religio (“whose realm, their religion”) by which a ruler chose whether their territory would be Catholic or Lutheran (then the only recognized Protestant sect). When the Catholic Holy Roman Emperor Ferdinand II became king of Bohemia in 1617, it upset his largely Protestant subjects, initiating the Bohemian Revolt - and the Thirty Years’ War – in May 1618 after the Second Defenestration of Prague and the Protestants support for their choice of monarch, Frederick V of the Palatinate.
Frederick V’s forces were defeated in 1620 at the Battle of White Mountain and Protestant Denmark engaged in the conflict in 1625, an event usually referenced as the first intervention of a foreign power in the war though, actually, the Dutch Protestants had been supplying Frederick V’s forces with arms and other resources since 1618 and Catholic Spain had supported Ferdinand II. The Protestant Christian IV of Denmark entered the war for religious reasons and to protect his commercial interests but also because King Gustavus Adolphus of Sweden was poised to enter the war as a Protestant champion, an honor Christian IV wanted for himself.
Christian IV was unable to match the strength of the Imperial forces under the Catholic mercenary leader Albrecht von Wallenstein, leading him to agree to peace terms and withdraw Denmark’s troops and Scottish mercenaries in 1629. Adolphus had supported Christian IV since 1628 but in 1630, with resources from the Catholic Cardinal Richelieu of France took the field against Wallenstein. Richelieu supported the Protestant king against Catholic Imperial forces in the interests of maintaining a balance of power between France and neighboring regions controlled by the powerful Habsburg Dynasty. After Adolphus was killed in battle in 1632, the Swedes continued the fight, supported by the French in the final, and bloodiest, phase of the war.
The Thirty Years' War concluded in 1648 with the Peace of Westphalia. While the treaty didn't declare a definitive winner, it had profound implications for European politics and international relations.
In terms of religion, the treaty largely reiterated the principles established by the Peace of Augsburg in 1555. However, its broader significance lies in its political and territorial consequences. The Peace of Westphalia reshaped the European map, recognizing the sovereignty of individual states. and laying the foundation for the modern international system, characterized by the principle of state sovereignty and non-interference in domestic affairs.
The Thirty Years’ War is recognized as the “official” end of the Protestant Reformation as, by the time it concluded, Calvinism was accepted along with Lutheranism and Catholicism as a legitimate belief system and so the period of the development of Protestant sects is thought to have concluded by 1648 – though this did nothing to resolve religious conflict going forward and, according to some scholars, the reformation is ongoing today. The war is also understood as the beginning of modern warfare as practiced by Adolphus Gustavus and the establishment of the modern international system of statehood, marking the conflict as a watershed event in the transition to the modern era.