WLADISLAUS II., JAGIELLO (1350-1434), king of Poland, was one of the twelve sons of Olgierd, grand-duke of Lithuania, whom he succeeded in 1377. From the very beginning of his reign Jagiello was involved hi disputes with the Teutonic Order, and with his uncle, the valiant Kiejstut, who ruled Samogitia independently. By the treaty of Dawidyszek (June i, 1380) he contracted an alliance with the knights, and two years later, acting on the advice of his evil counsellor, Wojdyllo, enticed Kiejstut and his consort to Krewo and there treacherously murdered them (Aug. 15, 1382). This foul deed naturally drove Witowt (?..), the son of Kiejstut, into the arms of the Order; but both princes speedily recognized that the knights were the real enemies of Lithuania, and prudently composing their differences invaded Prussian territory. This was the beginning of the fifty years' struggle with the Teutonic Order which was to make the reign of Jagiello so memorable. He looked about him betimes for allies against the common enemy of the Slavonic races, and fortune singularly favoured him. The Poles had brought their young queen Jadwiga home from Hungary, and in 1384 Jagiello sent a magnificent embassy to Cracow offering her his hand on condition that they shared the Polish crown. Jadwiga had long been betrothed to William of Austria; but she sacrificed her predilections for her country's good. On the i sth of February 1386 Jagiello, who had previously been elected king of Poland under the title of Wladislaus II., accepted the Roman faith in the cathedral of Cracow, and on the 18th his espousals with Queen Jadwiga were solemnized.
Jagiello's first political act after his coronation was the conversion of Lithuania to the true religion. This solemn act was accomplished at Yilr>a. the Lithuanian capital, on the i/th of February 1387, when a stately concourse of nobles and prelates.
headed by the king, proceeded to the grove of secular oaks beneath which stood the statue of Perkunos and other idols, and in the presence of an immense multitude hewed down the oaks, destroyed the idols, extinguished the sacred fire and elevated the cross on the desecrated heathen altars, 30,000 Lithuanians receiving Christian baptism. A Catholic hierarchy was immediately set up. A Polish Franciscan, Andrew Wassilo, was consecrated as the first Catholic bishop of Vilna, and Lithuania was divided ecclesiastically into seven dioceses. Mainly on the initiative of Queen Jadwiga, Red Russia with its capital the great trading city of Lemberg was persuaded to acknowledge the dominion of Poland; and there on the 27th of September 1387 the hospodars of Walachia and Moldavia for the first time voluntarily enrolled themselves among the vassals of Poland.
With savage Lithuania converted and in close alliance with Catholic Poland, the Teutonic Order was seriously threatened. The knights endeavoured to re-establish their position by sowing dissensions between Poland and Lithuania. In this for a time they succeeded (see WITOWT); but in 1401 Jagiello recognized Witowt as independent grand-duke of Lithuania (union of Vilna, January 18, 1401), and their union was cemented in the battle of Griinewald, which shook the whole fabric of the Teutonic Order to its very foundations. Henceforth a remarkable change in the whole policy of the Order was apparent. The struggle was no longer for dominion but for existence. Fortunate for them, in Jagiello they possessed an equally cautious and pacific opponent. Wladislaus II., in sharp contrast to Witowt, was of anything but a martial temperament. He never swerved from his main object, to unite Poland and Lithuania against the dangerous denationalizing German influences which environed him. But he would take no risks and always preferred craft to violence. Hence his leaning upon the holy see in all his disputes with his neighbours. Hence, too, his moderation at the peace of Thorn (ist of February 1411), when the knights skilfully extricated themselves from their difficulties by renouncing their pretensions to Samogitia, restoring Dobrzyn and paying a war indemnity; Jagiello was content to discredit them rather than provoke them to a war & outrance. Equally skilful was Jagiello's long diplomatic duel with the emperor Sigismund, then the disturbing element of Central Europe, who aimed at the remodelling of the whole continent and was responsible for the first projected partition of Poland.
Jagiello was married four times. At the dying request of the childless Jadwiga he espoused a Styrian lady, Maria Cillei, who bore him a daughter, also called Jadwiga. His third wife, Elizabeth Grabowska, died without issue, and the question of the succession then became so serious that Jagiello's advisers counselled him to betroth his daughter to Frederick of Hohenzollern, who was to be educated in Poland as the heir to the throne. But in 1422 Jagiello himself solved the difficulty by wedding Sonia, princess of Vyazma, a Russian lady rechristened Sophia, who bore him two sons, Wladislaus and Casimir, both of whom ultimately succeeded him. Jagiello died at Grodko near Lemberg in 1434. During his reign of half a century Poland had risen to the rank of a great power, a position she was to retain for nearly two hundred years under the dynasty which Jagiello had founded.
See August Sokolowski, History of Poland, vol. i. (Pol.) (Vienna, 1903); Carl Edward Napierski, Russo-Lithuanian Acts (Rus.) (St Petersburg, 1868); Monumenta Medii Aeri (Cracow, 1882); Karol Szajnocha, Jadwiga and Jagiello (Pol.) (Lemberg, 1855-1856)
Note - this article incorporates content from Encyclopaedia Britannica, Eleventh Edition, (1910-1911)