Short answers, pulled from the story.
Alexander Nevsky was Prince of Novgorod and Grand Prince of Vladimir from 1252 to 1263. He became famous for defeating Swedish invaders at the Battle of the Neva in 1240 and German crusaders at the Battle on the Ice in 1242, and he was later canonized as a saint of the Russian Orthodox Church.
Alexander received the sobriquet Nevsky, meaning of the Neva, after his victory over a Swedish army at the Battle of the Neva on the 15th of July 1240. The title was attached to him in the 15th century, roughly two centuries after the battle.
The Battle on the Ice was fought on the 5th of April 1242 at Lake Peipus, where Alexander Nevsky defeated the Livonian heavy cavalry led by Hermann of Dorpat. Later in 1242 the Germans agreed to relinquish occupied Russian territory and exchange prisoners of war.
Alexander Nevsky agreed to pay tribute to the Golden Horde so he could preserve the Eastern Orthodox Church while fighting enemies to the west and south. In 1259 he led an army to force Novgorod to pay tribute it had previously refused, and some historians criticize this as helping ensure Mongol dominance over Russia.
Alexander Nevsky was canonized as a saint of the Russian Orthodox Church by Macarius, Metropolitan of Moscow, in 1547. His remains had been found incorrupt in 1380 before the Battle of Kulikovo and placed in a shrine.
Alexander Nevsky died on the 14th of November 1263 in the town of Gorodets-on-the-Volga while returning from a diplomatic mission to Berke, leader of the Golden Horde, at Sarai. He was buried on the 23rd of November 1263 in the Monastery of the Nativity of the Holy Mother of God in Vladimir.
The 1938 film Alexander Nevsky, made by Sergei Eisenstein with a score by Sergei Prokofiev, depicts Alexander's victory over the Teutonic Knights as a parable of German aggression. It cemented the storyline of Nevsky as the savior of Russia, and Joseph Stalin re-released it in 1941 to mobilize Russian patriotism.