Władysław II Jagiełło

Here is a revised and improved memorial biography for Władysław II Jagiełło, refined with caution to include only well-supported facts and verified details:

Władysław II Jagiełło (born perhaps around 1362 in Vilnius; died 1 June 1434 at Gródek, often referred to as Jagiellonian Gord) was both Grand Duke of Lithuania and King of Poland, and the founder of the Jagiellonian dynasty. The exact year of his birth remains uncertain—many sources cite circa 1352 or circa 1362, with more recent research favoring around 1362 (en.wikipedia.org). He died on 1 June 1434 at Gródek (Gródek Jagielloński), then part of the Kingdom of Poland (en.wikipedia.org).

He ascended as Grand Duke of Lithuania in May 1377, following the death of his father, Algirdas. He ruled in this capacity until August 1381, resumed the title in August 1382, and from 1401 onward held the title of Supreme Duke, with his cousin Vytautas acting as Grand Duke (en.wikipedia.org). In 1386, following the Union of Krewo, he married Queen Jadwiga of Poland, was baptized as a Catholic with the Christian name Władysław, and was crowned King of Poland on 4 March 1386 (en.wikipedia.org).

His reign in Poland began as co-monarch with Jadwiga until her death in 1399, after which he ruled as sole monarch until his own death in 1434 (en.wikipedia.org). His reign oversaw the formal Christianization of Lithuania—he had himself baptized in February 1386 and initiated the establishment of bishoprics and churches; by 1387, Lithuania had begun converting to Catholicism (en.wikipedia.org).

Władysław II Jagiełło played a pivotal role in consolidating the Polish–Lithuanian union and leading the allied forces to victory over the Teutonic Order at the Battle of Grunwald in 1410. This triumph, followed by the Peace of Thorn, secured borders and elevated the union's standing in Europe (en.wikipedia.org). He also enacted significant legal privileges for the nobility—for example, the Horodło Union of 1413 tied Lithuania more closely to Poland, extending noble rights to Lithuanian elites (en.wikipedia.org).

Through his marriages—first to Jadwiga (d. 1399) and later to three other wives—he fathered children who carried forward the Jagiellonian line. His dynastic efforts ensured that his sons, including future kings Władysław III and Casimir IV, would succeed him, though he had to grant substantial noble privileges to secure their succession (en.wikipedia.org).

His reign is seen as a turning point in the medieval history of Central Europe, initiating centuries of Polish–Lithuanian union under the Jagiellonian dynasty.