The Battle of Grunwald or Battle of Tannenberg (called also Battle of Zalgiris by Lithuanians, and Battle of Tannenberg/Stebark by the Germans) occurred July 15 1410. It was fought in the plains beetween the villages of Grunwald, Stębark (Tannenberg) and Łodwigowo - currently in Poland.
It was a battle between two alliances. The one side was the Polish-Lithuanian Commonwealth (the Polish and Lithuanian forces), supported by the Bohemian, Ruthenian and Tatar forces, under the command of the king of Poland and grand duke of Lithuania, Wladyslaw Jagiello (Jogaila) (about 39,000 troops). On the other side, forces of the Teutonic Knights and some Western European knights (about 27,000 troops) under the Grand Master of the Teutonic Order Ulrich von Jungingen.
After the initial failure to break the left flank of the Teutonic forces, Lithuanian light cavalry had to retreat into marshes. Jagiello ordered an all-out assault of the right flank and the enemy lines were finally broken by heavy cavalry.
The Battle was won by Jagiello's forces. Ulrich von Jungingen died in battle, probably killed by polish peasantry while retreating to his camp. After the battle polish and lithuanian forces laid siege upon Marienburg castle, but it was ineffective and the siege was lifted shortly afterwards.
After the battle a peace in Torun (1411) was concluded in which Poland recovered Dobrzyn Land and Lithuania recovered Samogitia. This is thought to be a diplomatic defeat of Poland as there were attepts to abolish the Teutonic Knights state altogether. The indirect result of the battle was the disappearance of the victorious order myth, and the rising of the taxes by the Order which led to the Prussian Confederation uprising. After this battle the Teutonic Knights never regained their previous power, but the conflict was resolved in a series of wars ending in the Thirteen Years' War
To commemorate the medieval battle thousands of modern knighs from all across Europe gather every year in July at the Grunwald fields to fight the battle again. Great care is put to the historical details of the armour, weapons and the conduct of the battle.