Stay hidden! Get your head...
~ Vasili warning Tanya to stay out of the Major's sights

Vasili Grigoryevich Zaitsev is the main protagonist in the 2001 movie Enemy at the Gates. He is based on the late Vasili Zaitsev, who was a sniper in WW2, later in civil life as a engineer. He is portrayed by Jude Law, who also portrayed Dr. John Watson in the flim version of Sherlock Holmes. 

Events of the Flim 

Vasili participated at the Battle of Stalingrad, crossing the Volga River. That day, he met Commissar Danilov, alone and pinned down. Danilov gave Vasili his rifle and with it, killed 5 Germans without missing a shot, exhausting the last of Danilov's ammo, and Vasili returned the rifle to the Commissar (since his marksman skills were learned after his grandfather and younger brother)  

Because of this, Vasili was then transferred to a Soviet sniper division, and befriended Danilov, now a Senior Lieutenant, but both men took a romantic intrest to Tania Chernova, who was a member of the local militia, but was transferred to the intelligence division on orders of Danilov. 

When the Red Army found out that Erwin Konig, a Bavarian aristocrat and sniping instructor, was dispatched to kill Zaitsev, they sent Nikolai Kulikov, to help Vasili kill Konig. 

While on the lookout for Germans and Konig himself, Kulikov, while jumping to a gap with Vasili, is killed by a very skillful shot by Konig, shaking Vasili's sprits considerably but was able to shake off the feeling. 

Sasha Filippov, a young Russian double agent, worked for Konig by giving him wrong information about Vasili's whereabouts, giving Zaytsev a chance to ambush him but with alongside Tanya, he places a trap but only shoots him in the hand. At the 2nd attempt, Vasili falls asleep as a German soldier steals his sniper log. The general who commands Konig plans to take him home, but Konig doesn't believe that Vasili is dead. 

Vasili later shares a romantic moment with Tanya, but Danilov, jealous at Vasili and Tanya, disparages Vasili to his superiors. 

Later, at the final standoff between himself and Konig, Vasili places a trap to kill the Major, but Konig anticipates this and kills Sasha, knowing that he works with Vasili then hangs his body to a pole to bait him, but fails. Vasili vows to kill Konig and orders Tanya and Danilov to evacuate Sasha's mother out of the city, but Tanya is wounded by shrapnel while doing so. Danilov, thinking that Tanya is dead, regrets his jealousy and disenchantment to the Soviet communism cause. Because of this, he sacrifices himself to give Vasili a chance to kill the Major, which is successful as Konig, thinking that he killed Vasili, moves out of his position to check the body, but is too late as Zaytsev stands ready to kill him. Vasili kills Konig and takes his gun, placing it next to Danilov's corpse. 

At the end of the Battle of Stalingrad, Vasili visits Tanya, who is alive but recovering in a field hospital.

In real life history 

Portrayed after the late Vasili Zaitsev, who was buried in Kiev instead of Volgograd, Zaytsev published a memoir based in his experience in WW2 before his death, but his relationship with Tanya was not written on the memoir. Vasili killed the German sniper Erwin Konig in WW2, but his name did not appear on any of the German records. Vasili later adapted a civilian life in Kiev, Ukraine and graduated from textile college before taking a job as an engineer. Later he became the director of a textile factory. 10 days before the Soviet Union was disbanded, he died and was buried in Kiev (despite his last request was to be buried in Volograd)