The Warsaw Uprising (Polish: powstanie warszawskie; German: Warschauer Aufstand) was a major World War II operation, in the summer of 1944, by the Polish underground resistance, led by the Polish resistance Home Army (Polish: Armia Krajowa), to liberate Warsaw from German occupation. The uprising was timed to coincide with the retreat of the German forces from Poland ahead of the Soviet advance. While approaching the eastern suburbs of the city, the Red Army temporarily halted combat operations, enabling the Germans to regroup and defeat the Polish resistance and to destroy the city in retaliation. The Uprising was fought for 63 days with little outside support. It was the single largest military effort taken by any European resistance movement during World War II.
The Uprising began on 1 August 1944 as part of a nationwide Operation Tempest, launched at the time of the Soviet Lublin–Brest Offensive. The main Polish objectives were to drive the Germans out of Warsaw while helping the Allies defeat Germany. An additional, political goal of the Polish Underground State was to liberate Poland's capital and assert Polish sovereignty before the Soviet-backed Polish Committee of National Liberation could assume control. Other immediate causes included a threat of mass German round-ups of able-bodied Poles for "evacuation"; calls by Radio Moscow's Polish Service for uprising; and an emotional Polish desire for justice and revenge against the enemy after five years of German occupation.