Which treaty, signed in 1648, is often associated with the rise of the modern state system?

The Peace of Westphalia, signed in 1648, is often associated with the rise of the modern state system.

The term refers mainly to the treaties of Münster and Osnabrück, which ended the Thirty Years’ War in the Holy Roman Empire and the Eighty Years’ War between Spain and the Dutch Republic. Negotiations lasted several years and involved numerous European powers, making the settlement a major diplomatic achievement.

The agreements recognized the independence of the Dutch Republic and Switzerland and adjusted territories within the Holy Roman Empire. They also confirmed earlier arrangements concerning religious rights, especially for Catholic, Lutheran, and Calvinist communities. The settlement strengthened the authority of territorial rulers over religious affairs in many parts of the empire.

Later political thinkers and textbooks used “Westphalian sovereignty” to describe states as formally independent authorities within their territories. Historians caution that the treaties did not suddenly invent modern sovereignty; many older medieval institutions continued. Nevertheless, 1648 remains a useful landmark in the history of European diplomacy and international relations.