The
Battle of Grunwald,
First Battle of Tannenberg or
Battle of Žalgiris, was fought on 15 July 1410 during the
Polish–Lithuanian–Teutonic War. The alliance of the
Kingdom of Poland and the
Grand Duchy of Lithuania, led respectively by King
Wladyslaw II Jagiello (Jogaila) and Grand Duke
Vytautas (Witold; Vitaut), decisively defeated the German–Prussian
Teutonic Knights, led by Grand Master
Ulrich von Jungingen. Most of the Teutonic Knights' leadership were killed or taken prisoner. Although defeated, the Teutonic Knights
withstood the siege of their fortress in Marienburg (
Malbork) and suffered minimal territorial losses at the
Peace of Thorn (1411) (
Torun), with other territorial disputes continuing until the
Peace of Melno in 1422. The knights, however, would never recover their former power, and the financial burden of
war reparations caused internal conflicts and an economic downturn in the lands under their control. The battle shifted the balance of power in Eastern Europe and marked the rise of the
Polish–Lithuanian union as the dominant political and military force in the region.