LADISLAO III, Jagellon, king of POLAND. — Son of Ladislao II, born in Kraków in 1424, he assumed power in 1438.
In continuing his father’s policy, faced with the spread of Hussitism in Poland, he relied entirely on the Catholic party, led by the bishop of Kraków and future cardinal Zbigniew Oleśnicki, whose programme was the struggle against Hussitism, against the Czechs (who held Silesia), and union with Hungary in order to confront the Turkish threat. After the Hussite movement had been defeated, L. III was elected king of Hungary (1440). This election drew Poland, for the first time, into the struggle against the Turks, and L., in a successful campaign, managed to defeat them (August 1444), but was subsequently defeated at Varna on 10 November 1444, where he lost his life.