Deluge (history) - Swedish Invasion

Swedish Invasion

Following the Thirty Years' War, the Swedish Empire emerged as one of the strongest nations on the continent. It had a large army but little money to pay its soldiers. The Polish - Lithuanian Commonwealth, weakened by wars with the Cossacks and Tsardom of Russia, seemed like easy prey. Furthermore, Swedes remembered claims to their throne by Polish kings Sigismund III Vasa and his sons Władysław IV Vasa and John II Casimir, who themselves belonged to the House of Vasa. An earlier conflict, the Polish–Swedish War (1626–1629) had ended with the Treaty of Stuhmsdorf.

The Polish–Lithuanian King John II Casimir (reigned 1648–1668) lacked support amongst the Commonwealth nobility (szlachta) due to his sympathies with absolutist Austria and his open contempt for the "Sarmatist" culture of the nobility. Earlier, in 1643, John Casimir had become a member of the Jesuits and had received the title of Cardinal. Nevertheless, in December 1646 he returned to Poland and, in October 1647, resigned his position as Cardinal to stand for election to the Polish throne. He became King in 1648. However, some of the nobility supported Charles Gustav (King of Sweden from 1654 to 1660 and John Casimir's cousin) for the Polish–Lithuanian throne. Many members of the Polish nobility, including Deputy Chancellor of the Crown Hieronim Radziejowski and Grand Treasurer of the Crown Bogusław Leszczyński, regarded John Casimir as a weak king or as a "Jesuit-King"; for this or for personal reasons (i.e. Leszczyński was Protestant and Radziejowski was an old enemy of the Polish King who had banished him from Poland to exile in Sweden), they encouraged Charles Gustav to claim the Polish crown. Two Lithuanian noble princes, Janusz Radziwiłł and Bogusław Radziwiłł, subsequently introduced internal dissension into the Commonwealth's troubles and began negotiations with the Swedish king Charles X Gustav of Sweden aimed at breaking up the Commonwealth and the Polish–Lithuanian union. They signed the Treaty of Kėdainiai (1655), which envisaged the Radziwiłł princes ruling over two Duchies carved out from the lands of the Grand Duchy of Lithuania under Swedish vassalage (the Union of Kėdainiai).