Here are the first two paragraphs of the Wikipedia article on the **Treaty of Westphalia** (which is formally titled "Peace of Westphalia" on the site).
*Note: Because Wikipedia is a collaboratively edited, living document, the exact phrasing can change slightly from day to day. This reflects the stable, current version of the article's introduction:*
The **Peace of Westphalia** 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. The Eighty Years' War (1568–1648) between Spain and the Dutch Republic was also brought to an end with the Peace of Münster, which was signed in January 1648 and ratified in May of that year.
The peace negotiation involved a total of 109 delegations representing European powers, including Holy Roman Emperor Ferdinand III, Philip IV of Spain, the Kingdom of France, the Swedish Empire, the Dutch Republic, the princes of the Holy Roman Empire, and sovereigns of the free imperial cities. The treaties that made up the peace were the Treaty of Peace between Spain and the Netherlands, signed at Münster on 30 January 1648; and two complementary treaties both signed on 24 October 1648: the Treaty of Münster (*Instrumentum Pacis Monasteriense*, IPM), between the Holy Roman Emperor and France, along with their respective allies, and the Treaty of Osnabrück (*Instrumentum Pacis Osnabrugense*, IPO), between the Holy Roman Emperor and Sweden, along with their respective allies.