Polish-Lithuanian Union

The Polish-Lithuanian Union was a formal political alliance established in 1569, creating a single, dynastic state called the Polish-Lithuanian Commonwealth. It united the Kingdom of Poland and the Grand Duchy of Lithuania under a shared monarchy, common parliament, and coordinated foreign policy, while maintaining their own laws and institutions. This union allowed these neighboring states to strengthen their defenses against external enemies, promote economic growth, and preserve their cultural identities. It was one of Europe's largest and most populous countries in the 16th and 17th centuries, remaining in place until its formal dissolution in the late 18th century due to internal conflicts and external pressures.