The Treaty of Westphalia is signed.

The Peace of Westphalia refers to the pair of treaties signed in October and May 1648 which ended both the Thirty Years’ War and the Eighty Years’ War. The treaties were signed on October 24 and May 15, 1648 and involved the Holy Roman Emperor Ferdinand III, the other German princes, Spain, France, Sweden and representatives from the Dutch republic. The Treaty of the Pyrenees, signed in 1659, ending the war between France and Spain, is also often considered part of the treaty.

The peace as a whole is often used by historians to mark the beginning of the modern era. Each ruler would have the right to determine their state’s religion—thus, in law, Protestantism and Catholicism were equal. The texts of the two treaties are largely identical and deal with the internal affairs of the Holy Roman Empire.

The Peace of Westphalia continues to be of importance today, with many academics asserting that the international system that exists today began at Westphalia. Both the basis and the result of this view have been attacked by revisionist academics and politicians alike, with revisionists questioning the significance of the Peace, and commentators and politicians attacking the “Westphalian System” of sovereign nation-states. The concept of each nation-state, regardless of size, as of equal legal value informed the founding of the United Nations, where all member states have one vote in the General Assembly. In the second half of the twentieth century, the democratic nation state as the pinnacle of political evolution saw membership of the UN rise from 50 when it was founded to 192 at the start of the twenty-first century. However, many new nations were artificial creations from the colonial division of the world, reflecting the economic interests of the colonizers rather than local cultural, ethnic, religious or other significant boundaries which serve as the foundation of cohesive societies.

Peace negotiations between France and the Habsburgs began in Cologne in 1641. These negotiations were initially blocked by Cardinal Richelieu of France, who insisted on the inclusion of all his allies, whether fully sovereign countries or states within the Holy Roman Empire. In Hamburg and Lübeck, Sweden and the Holy Roman Empire negotiated the Treaty of Hamburg with the intervention of Richelieu. The Holy Roman Empire and Sweden declared the preparations of Cologne and the Treaty of Hamburg to be preliminaries of an overall peace agreement.

Dutch envoy Adriaan Pauw enters Münster around 1646 for the peace negotiations
The main peace negotiations took place in Westphalia, in the neighboring cities of Münster and Osnabrück. Both cities were maintained as neutral and demilitarized zones for the negotiations.

In Münster, negotiations took place between the Holy Roman Empire and France, as well as between the Dutch Republic and Spain. Münster had been, since its re-Catholicisation in 1535, a strictly mono-denominational community. It housed the Chapter of the Prince-Bishopric of Münster. Only Roman Catholic worship was permitted, while Calvinism and Lutheranism were prohibited.

Sweden preferred to negotiate with the Holy Roman Empire in Osnabrück, controlled by the Protestant forces. Osnabrück was a bidenominational Lutheran and Catholic city, with two Lutheran churches and two Catholic churches. The city council was exclusively Lutheran, and the burghers mostly so, but the city also housed the Catholic Chapter of the Prince-Bishopric of Osnabrück and had many other Catholic inhabitants. Osnabrück had been subjugated by troops of the Catholic League from 1628 to 1633 and then taken by Lutheran Sweden.