WLADISLAUS II., JAGIELLO (1350-1434), king of Poland, was one of the 12 sons of Olgierd, grand-duke of Lithuania, whom he suc ceeded in 1377. From the first Jagiello was involved in disputes with the Teutonic Order, and with his uncle, Kiejstut, who ruled Samogitia independently. By the Treaty of Dawidyszek (June 1, 1380) he contracted an alliance with the knights, and two years later, enticed Kiejstut and his consort to Krewo and there treacher ously murdered them (Aug. 15, 1382). This foul deed naturally drove Witowt (q.v.), the son of Kiejstut, into alliance with the Order. But the two soon made common cause against the knights and invaded Prussian territory. In search of allies, Wladislaus in 1384 offered his hand to Jadwiga, the young queen of Poland, on condition they shared the Polish crown. Jadwiga renounced her previous fiance, William of Austria. Jagiello was elected king of Poland as Wladislaus II. ; on Feb. 15, 1386, he adopted the Cath olic faith, and on Feb. 18 he married Jadwiga. He at once pro ceeded to convert Lithuania to his new faith. At Vilna, on Feb. 17, 1387, 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 dese crated heathen altars, 30,00o Lithuanians receiving Christian bap tism. A Catholic hierarchy was immediately set up. Ruthenia
with its capital Lemberg was persuaded to acknowledge the do minion of Poland; and there on Sept. 27, 1387, the hospodars of Walachia and Moldavia submitted voluntarily to Polish suzerainty.
The knights endeavoured to re-establish their position by sowing dissensions between Poland and Lithuania. In this for a time they succeeded (see WrrowT), but in 1401 Jagiello recognized Witowt as independent grand-duke of Lithuania (union of Vilna, Jan. 18, 1401), and their union was cemented in the battle of Griinewald, which shook the fabric of the Order to its foundations.
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, Eliza beth Grabowska, died without issue, and in 1422 Jagiello married 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 Poland had risen to the rank of a great power, a position she was to retain for nearly 200 years.