The Polish–Swedish War (1600–1611) was a continuation of struggle between Sweden and the Polish–Lithuanian Commonwealth over control of Livonia and Estonia, as well as the dispute over the Swedish throne between Charles IX of Sweden and Sigismund III of Poland. After skirmishes, sieges and battles often aborted by Jan Karol Chodkiewicz, a truce was signed until the later invasion by the Russians.

The monarchy of Sweden is centred on the monarchical head of state of Sweden, by law a constitutional and hereditary monarchy with a parliamentary system. There have been kings in what now is the Kingdom of Sweden for more than a millennium. Originally an elective monarchy, it became a hereditary monarchy in the 16th century during the reign of Gustav Vasa, though virtually all monarchs before that belonged to a limited and small number of political families which are considered to be the royal dynasties of Sweden.