The Battle on the Ice, alternatively known as the Battle of Lake Peipus (; ), took place on 5 April 1242. It was fought largely on the frozen Lake Peipus between the united forces of the Republic of Novgorod and Vladimir-Suzdal, led by Prince Alexander Nevsky, and the forces of the Livonian Order and Bishopric of Dorpat, led by Bishop Hermann of Dorpat.
The battle was significant because its outcome determined whether Western Catholicism or Eastern Orthodox Christianity would dominate in the region. In the end, the battle represented a significant defeat for the Catholic forces during the Northern Crusades and brought an end to their campaigns against the Orthodox Novgorod Republic and other Russian territories for the next century.
The significance and likely the scale of the battle was exaggerated in later Russian sources, which hailed it as one of the great Russian victories of the Middle Ages. The event portrayed in Sergei Eisenstein's historical drama film, Alexander Nevsky (1938), later created a popular but inaccurate image of the battle.
The Novgorodian victory is commemorated today in Russia as one of the Days of Military Honour.
Background
In 1221, Pope Honorius III was again worried about the situation in the Finnish-Novgorodian Wars after receiving alarming information from the Archbishop of Uppsala. He authorized the Bishop of Finland to establish a trade embargo against the "barbarians" that threatened Christianity in Finland. The nationality of the "barbarians", presumably a citation from Archbishop's earlier letter, remains unknown, and was not necessarily known even by the Pope. However, as the trade embargo was widened eight years later, it was specifically said to be against the Russians. Based on Papal letters from 1229, the Bishop of Finland requested the Pope enforce a trade embargo against Novgorodians on the Baltic Sea, at least in Visby, Riga and Lübeck. A few years later, the Pope also requested the Livonian Brothers of the Sword send troops to protect Finland. Whether any knights ever arrived remains unknown.
In 1237, the Swedes received papal authorization to launch a crusade, and in 1240, new campaigns began in the easternmost part of the Baltic region. After a successful campaign into Tavastia, the Swedes advanced further east until they were stopped by a Novgorodian army led by Prince Alexander Yaroslavich who had defeated the Swedes in the Battle of the Neva in July 1240 and received the nickname Nevsky.
Although the missionaries and Crusaders had attempted to establish peaceful relations with the Novgorod Republic, Livonian missionary and crusade activity in Estonia caused conflicts with Novgorod, who had also attempted to subjugate, raid and convert the pagan Estonians. The Estonians also sometimes attempted to ally with the Russians against the Crusaders, with the eastern Baltic missions constituting a threat to Russian interests and the tributary peoples. In 1240, the combined forces of the exiled prince of Pskov, Yaroslav Vladimirovich, and men from the Bishopric of Dorpat attacked the Pskov Republic and Votia, a tributary of Novgorod. This triggered the counterattack from Novgorod in 1241. The delayed response was a result of the internal strife in Novgorod.
Hoping to exploit Novgorod's weakness in the wake of the Mongol and Swedish invasions, the Teutonic Knights attacked the neighboring Novgorod Republic and occupied Pskov, Izborsk, and Koporye in the autumn of 1240. When they approached Novgorod itself, the local citizens recalled to the city 20-year-old Prince Alexander Nevsky, whom they had banished to Pereslavl earlier that year.
In regards to the pagans still living between Pskov and Novgorod and the Latin Christian settlements in Finland, Estonia and Livonia ("the land between christianized Estonia and Russia, meaning Votia, Neva, Izhoria, and Karelia"), a treaty was concluded in 1241 at Riga between the bishop of Ösel–Wiek and the Teutonic Order, which stipulated that the bishop was granted spiritual superiority in the newly conquered territories. The treaty indicated that the crusaders were well aware of the existence of these pagans.