WLADISLAUS III. (1424-1444), king of Poland and Hungary, the eldest son of Wladislaus II. Jagiello, by his fourth wife, Sophia of Vyazma, was born at Cracow on the 31st of October 1424, succeeding to the throne in his tenth year. The domestic troubles which occurred during his minority had an important influence upon the development of the Polish constitution; but under the wise administration of Zbigniew Olesnicki Poland suffered far less from her rebels than might have been anticipated, and Wladislaus gave the first proof of his manhood by defeating the arch-traitor Spytek of Melztyn in his camp at Grotnik on the 4th of May 1439. On the sudden death of the emperor Albert, who was also king of Bohemia and Hungary, the Hungarians elected Wladislaus as their king, despite the opposition of the widowed empress Elizabeth, already big with the child who subsequently ascended the Hungarian throne as Wladislaus V. But Wladislaus III., who was solemnly crowned king of Hungary at Buda by the Magyar primate in July 1440, had to fight against the partisans of the empress for three years till Pope Eugenius IV. mediated between them so as to enable Wladislaus to lead a crusade against the Turks. War was proclaimed against Sultan Murad II. at the diet of Buda on Palm Sunday 1443, and with an army of 40,000 men, mostly Magyars, the young monarch, with Hunyadi commanding under him, crossed the Danube, took Nish and Sofia, and advancing to the slope of the Balkans, returned to Hungary covered with glory. Europe resounded with the praises of the youthful hero, and the Venetians, the Genoese, the duke of Burgundy and the pope encouraged Wladislaus to continue the war by offering him every assistance. But at this juncture the sultan offered terms to Wladislaus through George Brankovic, despot of Servia, and, by the peace of Szeged (July i, 1444), Murad engaged to surrender Servia, Albania and whatever territory the Ottomans had ever conquered from Hungary, including 24 fortresses, besides paying an indemnity of 100,000 florins in gold. Unfortunately, Wladislaus listened to the representations of the papal legate, Cardinal Julian Cesarini, who urged him in the name of religion to break the peace of Szeged and resume the war. Despite the representations of the Poles and of the majority of the Magyars, the king, only two days after solemnly swearing to observe the terms of the treaty, crossed the Danube a second time to cooperate with a fleet from the West which was to join hands with the land army at Gallipoli, whither also the Greeks and the Balkan Slavs were to direct their auxiliaries. But the Walachians were the sole allies of Hungary who kept faith with her, and on the bloody field of Varna, November the loth, 1444, Wladislaus lost his life'and more than a fourth of his army.
See Julian Bartoszewicz, View of the Relations of Poland with the Turks and Tatars (Pol.) (Warsaw, 1860); August Sokolowski, History of Poland, vol. ii. (Pol.) (Vienna, 1904) ; Ignetcz Acsady, History of the Hungarian Realm, vol. i. (Hung.) (Budapest, 1905).
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)