LADISLAO IV, Wasa, king of POLAND. — Son of Sigismund III Wasa, b. 9 June 1595, he succeeded in maneuvering skillfully between France and the Habsburgs during the Thirty Years’ War. He showed tolerance toward the Protestants and directed his attention especially to the Eastern question, defeating the Russians in the campaign of 1632–34.
His ambition to sit on the Swedish throne found no support among the Poles. After concluding an armistice with Sweden (1635), he was preparing to enter into war against the Turks when death overtook him at Merecs on 20 May 1648, precisely at the moment when the revolt of the Cossacks under Bohdan Chmielnickij broke out.
BIBL.: A. Szelagowski, Rozkład Rzeszy i Polska za Wł. IV (The Collapse of the Empire and Poland under L. IV), Kraków 1907.