Kingdom of France Spain and the Holy Roman Empire during the Thirty Years' War (1618–48) which had broken out in Germany. After the death of both king and cardinal, the Peace of Westphalia (1648) secured universal acceptance of Germany's political and religious fragmentation, but the Regency of Anne of Austria and her minister Cardinal Mazarin experienced a civil uprising known as the Fronde (1648–1653) which expanded into a Franco-Spanish War (1653–59). The Treaty of the Pyrenees (1659) formalised France's seizure (1642) of the Spanish territory of Roussillon after the crushing of the ephemeral Catalan Republic and ushered a short period of peace. The
Peace of Westphalia European issues of the time. Scholars of international relations have identified the Peace of Westphalia as the origin of principles crucial to modern international relations, including the inviolability of borders and non-interference in the domestic affairs of sovereign states. This system became known in the literature as Westphalian sovereignty. Although scholars have challenged the association with the Peace of Westphalia, the debate is still structured around the concept of Westphalian sovereignty. Peace of Westphalia The Peace of Westphalia () was a series of peace treaties signed between May and October 1648 in the Westphalian cities of Osnabrück and Münster, largely