The Warsaw Uprising (1 August – 2 October 1944) was a major World War II operation by the Polish underground resistance, led by the Home Army, to liberate Warsaw from German occupation. It was timed to coincide with the Soviet advance, but the Red Army halted at the city's outskirts, allowing the Germans to regroup and crush the rebellion after 63 days of fighting—the single largest military effort by any European resistance movement during the war. The uprising ended in surrender on 2 October 1944 when supplies ran out, and the Germans then deported civilians and systematically razed the city. Casualties were catastrophic: about 16,000 resistance fighters were killed, and between 150,000 and 200,000 Polish civilians died, mostly in mass executions. The defeat enabled the pro-Soviet Polish administration, rather than the London-based government-in-exile, to take control of Poland, which remained in the Soviet-aligned Eastern Bloc until 1989. Historians widely debate the uprising's impact, with many arguing that Joseph Stalin deliberately halted his forces to exhaust the Home Army, making the event a significant step toward the Cold War.