Nazi Germany and the Soviet Union had signed a non-aggression pact in Moscow, including secret protocols dividing parts of Eastern Europe into spheres of influence. Hitler broke the agreement by launching Operation Barbarossa in June 1941. Stalin had discounted numerous intelligence warnings that an invasion was imminent.

The invasion produced a vast Soviet literature of mobilisation, siege and survival. Anna Akhmatova's Courage and Aleksandr Tvardovsky's wartime poetry defended language and communal identity against an assault made more shocking by the broken pact.