The Thirty Years' War (AP Euro Lecture Notes)

The Thirty Years’ War was a European continental war that took place from 1618-1648 (thirty years!). Most of the fighting took place in the Holy Roman Empire, although the war grew to include European powers outside of the Empire. What began as a local, religious conflict became more and more continental and political with each expanding phase of the war.

Background

Martin Luther’s Reformation sharply divided German princes within the Holy Roman Empire, leading to conflict between the Catholic Hapsburg emperors and the princes (primarily in the northern part of the Empire) who adopted Lutheran Protestantism.  This led to several conflicts that ended with the Peace of Augsburg (1555), which established the principle of cuius regio, eius religio (whoever reigns, his religion) within the Holy Roman Empire.  According to the terms of the Peace of Augsburg, the Holy Roman Emperor renounced the right to enforce a single religion throughout the “Empire” and each prince could choose between establishing Catholicism or Lutheranism in the lands under his own control.

Calvinism, which was not established as a legal religion in the Empire by the Peace of Augsburg, spread throughout the Empire in spite of its prohibition, as Calvinists did not care whether their religion was legal or not.  The spread of Calvinism threatened the tranquility of the Empire, as did places like Bohemia (modern-day Czech Republic), where the ruler’s religion was different from that of the majority of the population.

The Thirty Years’ War began as a local religious conflict between the Catholic Holy Roman Emperor and his Protestant subjects in Bohemia, but grew into a continent-wide political conflict over the Balance of Power in Europe.

The Four Phases

The Thirty Years’ War is divided into FOUR PHASES: Bohemian, Danish, Swedish, and French.  The Bohemian Phase was purely a local, religious conflict.  With each successive phase, the war became more continental in scope, bloodier, and more focused on political power than religion.

The Bohemian Phase

Although ruled directly by the Catholic Hapsburgs, Bohemian Protestants enjoyed a generous level of religious toleration (by the standards of the time).  A Hapsburg ruler had issued a Letter of Majesty to the Bohemian Protestants guaranteeing their freedom to practice their religion.  This letter was revoked by Ferdinand II, a Jesuit-educated Hapsburg who had no interest in tolerating Protestantism in any form.

The conflict started with the Defenestration of Prague, in which two emissaries of the Holy Roman Emperor were thrown out of a window.  The emissaries somehow survived the 70 foot drop - how they did depends on who you ask (Catholics maintained that they were saved by the Virgin Mary and angels, while Protestants later wrote that they fell into a massive dung heap.).  Ferdinand took swift action against the rebels, defeating them decisively in the Battle of White Mountain (1620).  The first phase of the Thirty Years’ War concluded with the Catholics squarely on top.

de·fen·es·trate /dēˈfenəˌstrāt/ - to throw someone out of a window.

The Danish Phase

The King of Denmark - a Lutheran state immediately north of the Holy Roman Empire - responded by invading in order to help the Lutheran princes against the Emperor.  This ended up being a colossal failure, as his expected allies didn’t give him aid they had promised and he had underestimated the strength of the Imperial armies.  The Danish king retreated back into his own country with an army of Imperial mercenaries at his heels.

The Danish Phase concluded with the Catholics again firmly in the lead.  In 1629, Ferdinand issued the Edict of Restitution, which ordered the return of Catholic lands that had been taken over by Protestants since the Peace of Augsburg.

---

---

The Swedish Phase

The Protestant cause got a needed break when Gustavus Adolphus, the Lutheran King of Sweden, invaded the Holy Roman Empire at the head of a powerful army.  Gustavus Adolphus has been called the “father of modern warfare,” being one of the first military commanders to make use of mobile artillery on the battlefield.  He scored a decisive victory at the Battle of Breitenfield (1631), strengthening the Protestant cause.  

The Swedes were helped by financial support from the French, who decided to support the Protestant faction in spite of France being a Catholic country.  Cardinal Richelieu, the First Minister of France, was a politique in the vein of Henry IV, caring more about weakening the Hapsburgs than about what religion people professed in the Holy Roman Empire.

The Balance of Power

In the 17th century, the Habsburgs were the most powerful family in Europe, controlling Austria, the Holy Roman Empire, Spain, the Netherlands, and various other territories strewn throughout Europe. France found itself surrounded by Hapsburg power and sought to change this by allying themselves with the Protestants (a deal with the devil?).

The French Phase

Gustavus Adolphus was killed in battle in 1632, ending Sweden’s active leadership in the Protestant cause. In the last phase of the Thirty Years’ War, the most dominant player on the Protestant side was Catholic France. Granted, the French had a bit of help from the Swedes, who had switched roles from fighter to financier. Here’s a device for remembering the roles of the Swedes and the French during the later phases of the Thirty Years’ War:

Swedish Phase

SWEDISH SWORDS
FRENCH FUNDS

French Phase

SWEDISH STACKS
FRENCH FISTS

---

The Peace of Westphalia (1648)

The last phase of the Thirty Years’ War was the bloodiest and failed to produce a decisive result.  After thirty years, people were weary of war and had lost track of why they were even fighting.  The warring parties gathered at Westphalia to hammer out a rational peace to end a long war that had begun as a local religious conflict.

By and large, the provisions of the Peace of Westphalia (1648) weakened the Holy Roman Emperor and established France as the dominant power in Western Europe. The Dutch Netherlands and Switzerland became independent and outside of Hapsburg influence, while France gained Alsace and Brandenburg - an ascendant Protestant kingdom in the Holy Roman Empire - gained territory, as well.

Calvinism was accepted as a third option for princes in the Holy Roman Empire to choose as an official religion and the freedom of private worship for religious minorities within the principalities of the Empire was guaranteed.  The goal here was to avoid future religious conflict.

The Thirty Years’ War was the last major religious war in Europe and put an end to the violence accompanying the Protestant Reformation.

For More Info:

Protestant Reformation Webpage

Video Lecture on YouTUbe