Forces of Novgorod led by Alexander Nevsky defeat the German knights of the Livonian Order on frozen Lake Peipus.
Date given in the Julian calendar.
During the Mongol invasion of Europe, Mongol forces defeat a Polish-led army in Silesia; two days later they rout the Hungarians at Mohi.
Mongol forces under Batu and Subutai rout the Hungarian army during the largest Mongol incursion into Europe.
Mongol armies under Batu devastate the Rus' principalities and take Kiev in 1240, beginning over two centuries of Golden Horde domination.
King John of England seals Magna Carta at Runnymede, subjecting royal power to the law.
The Venetian merchant Marco Polo travels to China under Kublai Khan; the account of his journey shapes European knowledge of Asia.
A coalition of Christian Iberian kingdoms defeats the Almohads, a major turning point of the Reconquista.