His own reign in Poland started in , upon the death of Queen Jadwiga, lasted a further thirty-five years, and laid the foundation for the centuries-long PolishโLithuanian 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 , [ nb 2 ] and became one of the most influential dynasties in late medieval and early modern Europe.
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 Order. The allied victory at the Battle of Grunwald in , followed by the Peace of Thorn , secured the Polish and Lithuanian borders and marked the emergence of the PolishโLithuanian alliance as a significant force in Europe.
Little is known of Jogaila's early life, and even his year of birth is uncertain. Previously historians assumed he was born in , but some recent research suggests a later dateโabout His name had a meaning of more courageous and superior than others, he spent most of his early time in Vilnius , at his father's manor.
The Grand Duchy of Lithuania to which Jogaila succeeded as Grand Duke in was a political entity composed of two leading, but very different nationalities and two political systems: ethnic Lithuania in the north-west and the vast Ruthenian territories of former Kievan Rus' , comprising the lands of modern Ukraine, Belarus, and parts of western Russia. At the start of his reign, Jogaila was preoccupied with unrest in the Lithuanian Rus' lands. In โ78, Andrei of Polotsk , the eldest son of Algirdas, challenged Jogaila's authority and sought to become Grand Duke.
