The Commonwealth was greatly weakened by a series of wars, beginning with the Khmelnytsky Uprising in Ukraine in 1648. During the Northern Wars of 1655–1661, the Lithuanian territory and economy were devastated by the Swedish army in an invasion known as the Deluge, and Vilnius was burned and looted by the Russian forces. Before it could fully recover, Lithuania was again ravaged during the Great Northern War of 1700–1721.