1410 -- The Battle of Tannenberg or Battle of Grunwald (called also Battle of Zalgiris by Lithuanians) occurred 15 July 1410 between Polish, Lithuanian, Russian and Tatar forces under the command of the Polish king Wladyslaw Jagiello (about 39,000 troops) against forces of the Teutonic Knights and its Bohemian and other allies (about 27,000 troops) under the Great Master of the Teutonic Order Ulrich von Jungingen.
The Battle was won by Jagiello's forces. Ulrich von Jungingen died in battle. After this battle the Teutonic Knights never regained its previous power.
See History -- Military history -- List of battles -- History of Poland -- History of Prussia -- History of Lithuania -- History of Poland.