Eighty Years' War other areas, although the heartland of the republic was no longer threatened; this included the beginnings of the Dutch Colonial Empire, which at the time were conceived as carrying overseas the war with Spain. After a 12-year truce in which the Dutch Republic achieved de facto recognition, hostilities broke out again around 1619, which can be said to coincide with the Thirty Years' War. An end was reached in 1648 with the Peace of Münster (a treaty part of the Peace of Westphalia), when the Dutch Republic was definitively recognised as an independent country no longer part of the Holy
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