Peace of Westphalia

The Peace of Westphalia refers to two treaties signed in 1648 in the Westphalian cities of Münster and Osnabrück: the Treaty of Münster (signed 24 October 1648) and the Treaty of Osnabrück (also 24 October 1648). Together with the earlier Peace of Münster between Spain and the Dutch Republic (30 January 1648), these agreements ended the Thirty Years' War (1618–1648) in the Holy Roman Empire and the Eighty Years' War between Spain and the United Provinces.

The principal parties included the Holy Roman Emperor Ferdinand III, the Kingdom of France, the Swedish Empire, Spain, the Dutch Republic, and the estates of the Holy Roman Empire. Key territorial and political outcomes included:

• Formal recognition of the independence of the Dutch Republic and the Swiss Confederation from imperial authority.
• Territorial gains for France (parts of Alsace) and Sweden (Western Pomerania, Bremen-Verden), giving Sweden a seat in the Imperial Diet.
• Extension of the 1555 Peace of Augsburg principle of cuius regio, eius religio to include Calvinism alongside Lutheranism and Catholicism.
• Recognition of the sovereignty of the roughly 300 imperial estates, including the right to conduct foreign policy, subject to limits on alliances against the Emperor.

In international relations theory, Westphalia is often invoked as the symbolic origin of the sovereign territorial state and the norms of territorial integrity, legal equality of states, and non-intervention in domestic affairs—collectively termed the "Westphalian system." Scholars such as Stephen Krasner (Sovereignty: Organized Hypocrisy, 1999) have argued this narrative overstates the treaties' actual content, noting that full juridical sovereignty developed gradually over the 18th and 19th centuries. Nevertheless, the term "Westphalian sovereignty" remains standard shorthand in diplomatic and academic discourse for the state-centric order that the UN Charter (1945) later codified in Article 2.