The Soviet Red Army liberated about 7,000 prisoners left behind by the Nazis in Auschwitz concentration camp.

The Workers' and Peasants' Red Army, often shortened to the Red Army, was the army and air force of the Russian Soviet Republic and, from 1922, the Soviet Union. The army was established in January 1918 by a decree of the Council of People's Commissars to oppose the military forces of the new nation's adversaries during the Russian Civil War, especially the various groups collectively known as the White Army. In February 1946, the Red Army was renamed the "Soviet Army". Following the dissolution of the Soviet Union it was split between the post-Soviet states, with its bulk becoming the Russian Ground Forces, commonly considered to be the successor of the Soviet Army.

On 27 January 1945, Auschwitz—a Nazi concentration camp and extermination camp in occupied Poland where more than a million people were murdered as part of the Nazis' "Final Solution" to the Jewish question—was liberated by the Soviet Red Army during the Vistula–Oder Offensive. Although most of the prisoners had been forced onto a death march, about 7,000 had been left behind. The Soviet soldiers attempted to help the survivors and were shocked at the scale of Nazi crimes. The date is recognized as International Holocaust Remembrance Day.

Nazi Germany, officially the German Reich and later the Greater German Reich, was the German state between 1933 and 1945, when Adolf Hitler and the Nazi Party controlled the country, transforming it into a totalitarian dictatorship. The Third Reich, meaning "Third Realm" or "Third Empire", referred to the Nazi claim that Nazi Germany was the successor to the earlier Holy Roman Empire (800–1806) and German Empire (1871–1918). The Third Reich, which the Nazis referred to as the Thousand-Year Reich, ended in May 1945, after 12 years, when the Allies defeated Germany and entered the capital, Berlin, ending World War II in Europe.