The Peace of Westphalia, October 24, 1648.

The Peace of Westphalia refers to two peace treaties signed on October 24, 1648, in the Westphalian cities of Münster and Osnabrück. The treaties put an end to the Thirty Years’ War (1618-1648) and brought peace to the Holy Roman Empire. 

Events Leading to the Peace of Westphalia

The Peace of Westphalia was primarily a response to the Thirty Years' War, which erupted in 1618. This conflict was a complex web of religious, political, and territorial disputes. Initially, it was a struggle between Protestant and Catholic states within the Holy Roman Empire, but it eventually engulfed most of Europe, inflicting widespread suffering marked by destruction, famine, and loss of life.

Concurrently, the Eighty Years' War was being fought between the Spanish Habsburg Monarchy and the Dutch Republic. The Dutch sought to gain independence from Spanish rule, and their struggle added to the turmoil in Europe. Moreover, the involvement of various foreign powers further complicated the situation. France supported the Protestant states in the Holy Roman Empire, while the Spanish Habsburgs received assistance from the Catholic Habsburgs in Austria. Sweden and Denmark also entered the conflict at different points, seeking to further their own interests.

By the mid-17th century, Europe was exhausted from decades of warfare, and no clear victor had emerged in the protracted conflicts. In the particularly contested regions, the population had fallen by more than half. This exhaustion created the conditions for negotiations and the desire for a lasting peace settlement.

The Peace of Westphalia

At Christmas 1641, the parties to the conflict agreed on peace negotiations in the Catholic city of Münster and in the Protestant town of Osnabrück, but it was not until December 1644 that the Peace Congress was finally opened. The negotiations involved a diverse set of participants, including representatives of the warring parties, major European powers, and minor states. The Holy Roman Empire, as one of the central parties to the conflict, played a pivotal role, as did Spain, France, Sweden, and the Dutch Republic. The Papal Nuncio and the Holy See also participated.

Four years later, on 24 October 1648, the Peace of Westphalia was signed. It consisted of two separate peace treaties: the Treaty of Münster and the Treaty of Osnabrück. On one hand, the Treaty of Münster, signed on May 15, 1648, brought an end to the Eighty Years' War between Spain and the Dutch Republic. Spain recognized the independence of the Dutch Republic, marking a major step in the formation of the modern Dutch state. On the other, the Treaty of Osnabrück, signed on October 24, 1648, ended the Thirty Years' War. Moreover, it included provisions to recognize the sovereignty of individual German states and promoted religious tolerance, attempting to put an end to religious conflicts in the Holy Roman Empire. In this regard, one of the most notable outcomes was the introduction of the principle of "cuius regio, eius religio," which allowed rulers to determine the religion of their territories, granting tolerance to both Catholics and Protestants. This made a significant shift from the earlier idea of universal Catholicism.

Lastly, the treaties brought about significant territorial changes. Numerous regions changed hands, and borders were redrawn, resulting in a transformed political landscape. Switzerland, for instance, gained formal recognition as an independent entity. Other territorial adjustments saw Pomerania being divided between Sweden and Brandenburg, France acquiring territories such as Metz, Toul, Verdun, and parts of Alsace, and Sweden obtaining Western Pomerania, Bremen, and Verden.

Legacy

The most immediate outcome of the Peace of Westphalia was the end of the devastating Thirty Years' War and the Eighty Years' War, ushering in a period of relative peace in Europe. Moreover, while the treaty's recognition of religious tolerance did not fully resolve religious tensions, it provided a framework for coexistence between Catholics and Protestants within individual states. In this sense, the negotiations at Westphalia set a precedent for resolving conflicts through diplomacy and negotiations rather than prolonged warfare.

The Peace of Westphalia is often regarded as the birth of the modern international system, as it established the principle of state sovereignty, emphasizing that states are the highest authority within their territories. This concept has been foundational in shaping international relations and the structure of nation-states. Additionally, the notion of a balance of power, articulated in the agreements, laid the groundwork for European diplomacy and played a central role in shaping the continent's political dynamics for centuries to come.