Sigismund, because he was the son of Swedish King John III, became King of Poland from 1587 and also King of Sweden from 1592-98. He moved the capital from Cracow to Warsaw somewhat cognizant of what was to come from the North. Reasonably secure on his southern border, Sigismund had to consider a growing Swedish power that resented both Poland and Sigismund because both were Roman Catholic and because the King of Poland supported the Counter Reformation while Sweden was solidly in the Protestant camp. Certain members of the aristocracy favoring reform revolted. Sigismund held onto the crown successfully leading campaigns in the east resulting in his conquering the Muscovite Boyars who offered the crown to his son Ladislaus.

Reigned 1587-1632