King of Poland and Grand Duke of Lithuania during the era of the Polish–Lithuanian Commonwealth, Duke of Opole in Upper Silesia, and titular King of Sweden 1648–1660. In Poland, he is known and commonly referred as Jan Kazimierz. His parents were Sigismund III Vasa (1566–1632) and Constance of Austria (1588–1631). His older brother, and predecessor on the throne, was Wladyslaw IV Vasa.
