Which battle in 1242 saw the Teutonic Knights defeated by Alexander Nevsky on a frozen lake?

The Battle on the Ice was the 1242 battle in which Alexander Nevsky’s forces defeated crusading forces on frozen Lake Peipus. Fought on 5 April 1242, it was a major confrontation in the Northern Crusades, the campaigns by Latin Christian powers and military orders to expand into the eastern Baltic. The opposing force included the Livonian Order, the Bishopric of Dorpat, Danish and German troops, and associated local forces.

Alexander, a prince of Novgorod and Vladimir, chose ground near Lake Peipus, which formed part of the frontier between Novgorodian lands and the crusader-held Baltic region. The battle ended in a victory for Novgorod and Vladimir-Suzdal. The Livonian forces withdrew, returned prisoners, and abandoned their immediate effort to seize more territory around Pskov.

The name “Battle on the Ice” is widely recognized, but the event is also called the Battle of Lake Peipus. Popular retellings often claim that large numbers of heavily armored knights fell through cracking ice. Medieval sources do not securely establish that dramatic scene; the battle was fought on or near the frozen lake, but the extent of ice breakage remains uncertain. The Teutonic Knights are often named in summaries, although the principal force was the Livonian branch and its allies.