(July 15, 1240), military engagement in which the Novgorod army defeated the Swedes on the banks of the Neva River; in honour of this battle the Novgorod commander, Prince Alexander Yaroslavich (Alexander Nevsky, Saint), received the surname Nevsky. The conflict between the Swedes and the Novgorodians was based largely on Swedish efforts to expand into northwestern Russia and to force the conversion of the Russians from Greek Orthodoxy to Roman Catholicism. Calculating that the Mongol conquest of Russia (1240) had deprived Novgorod of military support from other Russian cities, the Swedes, led by Earl Birger, landed at the Neva's mouth and attempted to block Novgorod's approach to the Baltic Sea. Alexander led an army against them and destroyed most of the Swedish force. Birger sailed back to Finland with the few Swedish survivors.