Charles X Gustav

Charles X Gustav (1622-1660), king of Sweden (1654-1660), the nephew of King Gustav II Adolph, born in Nyköping. The first Swedish ruler of the Palatinate dynasty, he became king when his cousin, Queen Christina, abdicated in his favor. Charles succeeded to the throne of an almost bankrupt kingdom; nevertheless, he hoped to increase the territory of the country at the expense of nations weakened by the Thirty Years' War (1618-1648). In 1655, on the pretext of preventing his cousin, King Jan II Kazimierz of Poland, from seizing the Swedish crown, Charles invaded Poland. He formed an alliance with Frederick William, elector of Brandenburg, and was victorious at Warsaw. Soon thereafter Russia, Denmark, and the Holy Roman Empire all declared war on Sweden, and Frederick William switched sides when the Poles agreed to recognize his territorial claims. Charles retired from Poland, but in 1658, leading his army across the frozen sea, he forced the Danes to capitulate. By the Treaty of Roskilde, King Frederick II of Denmark ceded all his lands in southern Sweden to Charles. Hoping for a total conquest of Denmark, Charles attacked again later in the year but was rebuffed by a stout Danish defense of Copenhagen. Charles died soon thereafter, and he was succeeded by his son Charles XI.