The siege of Leningrad started on 8 September 1941, when the last road to the city was severed. Although the Soviet forces managed to open a narrow land corridor to the city on 18 January 1943, the siege was not lifted until 27 January 1944, 872 days after it began.
It was one of the longest and most destructive sieges in history, and possibly the costliest in casualties suffered. Leningrad's capture was one of three strategic goals in the German Operation Barbarossa and the main target of Army Group North.
The strategy was motivated by Leningrad's political status as the former capital of Russia and the symbolic capital of the Russian Revolution, its military importance as a main base of the Soviet Baltic Fleet, and its industrial strength, housing numerous arms factories. By 1939, the city was responsible for 11% of all Soviet industrial output.