Battle of Grunwald Day is observed in Lithuania and Poland every July 15, commemorating the significant battle fought on the same date in 1410 between the Kingdom of Poland and the Grand Duchy of Lithuania against the German-Prussian Teutonic Knights. This battle is recognized as one of the largest in Medieval Europe and symbolizes national pride and resistance against invaders for both countries. Annually, Poland and Lithuania reenact the battle, with the most common day for these events being July 15, although reenactments can occur from July 11 to 15. The largest reenactment took place in 2010, marking the 600th anniversary of the battle, featuring about 4,000 knights and various medieval exhibitions. People from Poland, Lithuania, and other European nations gather to witness the reenactments and explore local exhibitions of medieval clothing and armor.