In 1644, with Europe torn by the Thirty Years’ War (1618–48), a peace conference was convened in Westphalia, Germany. But the negotiations were four long years in the making: the fighting continued until 1648, when the Peace of Westphalia was finally signed. Under this treaty, France and Sweden received some German lands. The agreement also made important allowances for Europe’s religions: Not only was Lutheranism given the same due as Catholicism, but Calvinism, the religious movement begun by Frenchman John Calvin (1509–1564), was also was given the official nod. In short, the treaty not only ended the religious warfare in Europe, but it provided for some measure of religious tolerance.

Since the pact recognized the sovereignty of all the states of the Holy Roman Empire, it effectively dissolved the empire. Therefore, historians view the Peace of Westphalia as the beginning of Europe’s modern state system.