Battle of Tannenberg (Grunwald) (1410)
The Battle of Tannenberg (Grunwald) was fought between the Knights of the Teutonic Order and Polish-Lithuanian forces led by Wladyslaw II Jagielo on July 15, 1410. One of the most significant battles of the Middle Ages was won by the Polish-Lithuanian forces and made the Polish-Lithuanian Union the leading power in the Eastern Europe. The Battle of Tannenberg also marked the beginning of the decline of the Monastic State of the Teutonic Knights that never recovered from the defeat. The Poles and Lithuanians dictated the terms of the peace treaty which did not resulted in severe territorial loss but ruined the treasury of the Teutonic Knights.