Battle on the Ice Day is observed in Russia on April 18 each year, commemorating the victory of the Republic of Novgorod over the Teutonic Knights in the historic Battle of Ice in 1242. This day is recognized as one of the Days of Military Honor in the Armed Forces of the Russian Federation, celebrating significant victories in Russian history. The battle, fought on the frozen Lake Pepius, was pivotal in halting the expansion of the Teutonic Order and establishing a boundary between Eastern Orthodoxy and Western Catholicism. The observance highlights the importance of the Novgorod Republic, which extended from the Baltic Sea to the Northern Urals, and honors Prince Alexander Nevsky, who led the defense against the Teutonic Knights. While primarily recognized within military contexts, some of these commemorative dates are also considered public holidays.