The Lithuanian–Russian Commonwealth was a political entity that existed from the late 16th century to the late 18th century, primarily involving the Grand Duchy of Lithuania and the Kingdom of Poland. This union aimed to strengthen both regions against external threats and to promote economic and cultural ties. It was characterized by a shared monarchy and a common parliament, known as the Sejm. The Commonwealth faced various challenges, including internal conflicts and external invasions, particularly from Russia and Sweden. Ultimately, it declined due to these pressures and was partitioned in the late 18th century, leading to the dissolution of the Commonwealth and the division of its territories among neighboring powers.