Ferdinand III, Holy Roman Emperor in the context of "Oedipus Aegyptiacus"

The Peace of Westphalia (German: Westfälischer Friede, pronounced [vɛstˈfɛːlɪʃɐ ˈfʁiːdə] ) is the collective name for two peace treaties signed in October 1648 in the Westphalian cities of Osnabrück and Münster. They ended the Thirty Years' War (1618–1648) and brought peace to the Holy Roman Empire, closing a calamitous period of European history that killed approximately eight million people. Ferdinand III, Holy Roman Emperor, the kingdoms of France and Sweden, and their respective allies among the princes of the Holy Roman Empire, participated in the treaties.

The negotiation process was lengthy and complex. Talks took place in two cities, because each side wanted to meet on territory under its own control. A total of 109 delegations arrived to represent the belligerent states, but not all delegations were present at the same time. Two treaties were signed to end the war in the Empire: the Treaty of Münster and the Treaty of Osnabrück. These treaties ended the Thirty Years' War in the Holy Roman Empire, with the Habsburgs (rulers of Austria and Spain) and their Catholic allies on one side, battling the Protestant powers (Sweden and certain Holy Roman principalities) allied with France (though Catholic, strongly anti-Habsburg under King Louis XIV).

Leopold I (Leopold Ignaz Joseph Balthasar Franz Felician; Hungarian: I. Lipót; 9 June 1640 – 5 May 1705) was Holy Roman Emperor, King of Germany, King of Hungary, Croatia, and Bohemia. The second son of Ferdinand III, Holy Roman Emperor, by his first wife, Maria Anna of Spain, Leopold became heir apparent in 1654 after the death of his elder brother Ferdinand IV. Elected in 1658, Leopold ruled the Holy Roman Empire until his death in 1705, becoming the second longest-ruling emperor (46 years and 9 months) of the House of Habsburg. He was both a composer and considerable patron of music.

Leopold's reign is known for conflicts with the Ottoman Empire in the Great Turkish War (1683–1699) and rivalry with Louis XIV, a contemporary and first cousin (on the maternal side; fourth cousin on the paternal side), in the west. After more than a decade of warfare, Leopold emerged victorious in the east thanks to the military talents of Prince Eugene of Savoy. By the Treaty of Karlowitz, Leopold recovered almost all of the Kingdom of Hungary, which had fallen under Turkish power in the years after the 1526 Battle of Mohács.

The Treaty of Münster of 24 October 1648 was a treaty signed in Münster between, on the one hand, the Kingdom of France with regent cardinal Jules Mazarin for the underage king Louis XIV of France, plus his allies, and, on the other hand, Holy Roman Emperor Ferdinand III and his allies.

Maria Anna of Spain (18 August 1606 – 13 May 1646) was a Holy Roman Empress and Queen of Hungary and Bohemia by her marriage to Ferdinand III, Holy Roman Emperor. She acted as regent on several occasions during the absences of her husband, notably during his absence in Bohemia in 1645.

The daughter of King Philip III of Spain and of Margaret of Austria, she was prior to her Imperial marriage considered a possible wife for Charles, Prince of Wales. The event, later known in history as the "Spanish match", provoked a domestic and political crisis in the kingdoms of England and Scotland. In the imperial court in Vienna, she continued to be strongly influenced by her native Spanish culture from clothes to music and also promoted the strengthening of relations between the Imperial and the Spanish branches of the House of Habsburg.

Archduke Leopold Wilhelm of Austria (5 January 1614 – 20 November 1662), younger brother of Emperor Ferdinand III, was an Austrian soldier, administrator and patron of the arts.

He held a number of military commands, with limited success, and served as Governor of the Spanish Netherlands, before returning to Vienna in 1656. Despite being nominated as Holy Roman Emperor after Ferdinand's death in 1657, he stood aside in favour of his nephew Leopold I.

Eleonora Gonzaga (18 November 1630 – 6 December 1686) was by birth Princess of Mantua, Nevers and Rethel from the Nevers branch of the House of Gonzaga, and was Holy Roman Empress, German Queen, Queen consort of Hungary and Bohemia by marriage to Emperor Ferdinand III.

Nicknamed the Younger (de: Jüngere) to distinguish herself from her namesake grandaunt, she was considered one of the most educated and virtuous women of her time. Fascinated by religious poetry, she founded a literary academy and was also a patron of musical theater. As Holy Roman Empress, she promoted the development of cultural and spiritual life at the Imperial court in Vienna, and despite being a staunch Catholic and benefactress of several monasteries, she had a tolerant attitude towards Protestantism.