Based on history, a Russian war hero rallies his people to defeat the invading Germans in 1242.
Prince Alexander Nevsky (Nikolai Cherkasov) tells Mongol warriors not to fight and is offered a command; but the Mongols move on. Alexander says they must fight the Germans first. In Novgorod Vasili Buslaj (Nikolai Okhlopkov) wants to marry; but Gavrilo (Andrei Abrikosov) asks Olga (Vera Ivashova) to choose between them. A wounded man warns that the Germans are coming. Some call for Alexander Nevsky; others turn to Domash (N. Arsky), who recommends Alexander. The Teutonic Knights' Grand Master (Vladimir Yershov) appoints princes, and a priest declares there can be only one Roman Emperor. A Russian prisoner is defiant, and soldiers wearing crosses toss children into fire.
At Pereslavl men from Novgorod call on Alexander and ask him to be prince again, because Pskov was taken. Alexander rouses the peasants. The moneyed men are told not to resist the peasants. Craftsmen promise to make lances, shields, and axes. Olga tells Buslaj and Gavrilo that she will wed the most valorous. German warriors pray before advancing in the snow. Alexander sees that Domash is dead and orders his men to fight on the frozen lake.
On April 5, 1242 the German cavalry advances and pushes back the battling Russians. Alexander waits and attacks from the flanks. Buslaj kills many and is assisted by female warrior Vasilisa (Aleksandra Danilova). Germans form strong lines as fighting continues. Gavrilo breaks through the line but is surrounded. Alexander fights the Grand Master on horseback, capturing him. Alexander shouts that they have won the day, and the Russians rout the Germans, who flee. Germans fall through breaking ice and drown. Alexander surveys the dead. Buslaj revives Gavrilov; Olga finds them and helps them walk. The bodies of Gavrilov and Buslaj lead the procession. Alexander and his army are cheered. Alexander tells the Russians to remember this battle and rise up when necessary or be punished. Alexander will ransom the knights. Buslaj revives and contradicts his mother by saying that Vasilisa and Gavrilov fought most bravely. Garvilov revives for Olga, and Buslaj will marry Vasilisa. Alexander says to be merry and drinks. He warns that those who come with the sword in hand will perish as Russians take their stand.
This historic film was clearly made as a warning to Nazi Germany, and Stalin ordered it shown in every theater to rouse the Russian people after the Nazi invasion of 1941. Alexander Nevsky had led the victory over the Swedes in 1240; but he was expelled for meddling in Novgorod affairs. Then he led this massacre of the Teutonic warriors in 1242. Years later he cooperated with Mongol conquerors in their taxing of the Russian people.