Britannica Sources used in this answer

Which agreement created the Polish-Lithuanian Commonwealth in 1569?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Map showing Poland's territory in 1634 under the reign of Wladyslaw IV Vasa, shaded in pink and spanning from the Baltic Sea in the north to near Kyiv in the southeast. Major present-day cities such as Warsaw, Krakow, Gdansk, Vilnius, Minsk, Lwow (Lviv), Pinsk, and Kyiv are marked within the territory, with surrounding cities like Moscow, Riga, Vienna, and Budapest shown for reference. — Polish-Lithuanian Commonwealth Poland's territory in 1634, during the reign of Władysław IV Vasa.

The Polish-Lithuanian Commonwealth was created by the Union of Lublin, a pact concluded on July 1, 1569.12

This agreement united Poland and Lithuania into a single, federated state ruled by a jointly selected sovereign. While the two nations remained distinct, equal components—each retaining its own laws, army, treasury, and administration—they agreed to cooperate on foreign policy and participate in a joint Sejm (legislature). The union was driven by the need for a more complete political integration, particularly as Sigismund II Augustus lacked heirs and the Lithuanian state faced external threats during the Livonian War.1