Short answers, pulled from the story.
Adolf Hitler launched Operation Barbarossa on the 22nd of June 1941. This invasion involved 3.3 million troops crossing the borders defined in the German-Soviet Nonaggression Pact.
Adolf Hitler's vision for the Eastern Front demanded Lebensraum or living space for the Germanic master race. This ideology required the enslavement or extermination of Slavic Untermenschen and the elimination of Jewish Bolshevik influence.
The Battle of Stalingrad ended on the 31st of January 1943 when the German 6th Army surrendered. This defeat shattered the myth of German invincibility and marked the beginning of a relentless Soviet advance.
The Red Army deployed over 2.3 million troops during Operation Bagration. This offensive destroyed Germany's Army Group Center and liberated Belarus.
The United States and the United Kingdom supplied 20% of Soviet military hardware through the Lend-Lease program. Between 1941 and 1945, the Allies shipped over 17 million tons of supplies to sustain the war effort.
The Red Army captured Berlin on the 2nd of May 1945. The German Instrument of Surrender was signed on the 8th of May 1945, ending the war in Europe.