King Wladislaus II of Poland
Jogaila (listen; c. 1352/1362 – 1 June 1434), later Władysław II Jagiełło (Polish pronunciation: [vwaˈdɨswaf jaˈɡʲɛwːɔ] (listen)) was Grand Duke of Lithuania (1377–1434) and then King of Poland (1386–1434), first alongside his wife Jadwiga until 1399, and then sole ruler of Poland. He ruled in Lithuania from 1377. Born a pagan, in 1386 he converted to Catholicism and was baptized as Władysław in Kraków, married the young Queen Jadwiga, and was crowned King of Poland as Władysław II Jagiełło. In 1387 he converted Lithuania to Christianity. His own reign in Poland started in 1399, upon the death of Queen Jadwiga, lasted a further thirty-five years, and laid the foundation for the centuries-long Polish–Lithuanian union. He was a member of the Jagiellonian dynasty in Poland that bears his name and was previously also known as the Gediminid dynasty in the Grand Duchy of Lithuania. The dynasty ruled both states until 1572, and became one of the most influential dynasties in late medieval and early modern Europe. During his reign, the Polish-Lithuanian state was the largest state in the Christian world.Jogaila was the last pagan ruler of medieval Lithuania. After he became King of Poland, as a result of the Union of Krewo, the newly formed Polish-Lithuanian union confronted the growing power of the Teutonic Knights. The allied victory at the Battle of Grunwald in 1410, followed by the Peace of Thorn, secured the Polish and Lithuanian borders and marked the emergence of the Polish–Lithuanian alliance as a significant force in Europe. The reign of Władysław II Jagiełło extended Polish frontiers and is often considered the beginning of Poland's Golden Age.