On October 2, 1944, the commanders of the Polish Home Army signed the capitulation of Warsaw at German headquarters in Ozarow, ending an uprising that had begun on August 1. Fighters marched out into captivity. Around 16,000 of them had been killed, and civilian deaths are usually put between 150,000 and 200,000. What was left of the city was then deliberately destroyed, building by building, on Himmler's order.
The timing had been chosen for political reasons. The Soviet army had reached the east bank of the Vistula in late July and was broadcasting calls for a rising, and the Home Army wanted to take the capital itself before the Red Army arrived, so that the London government-in-exile would have something to negotiate with. The assumption was that the offensive would continue. It did not. The Soviet 2nd Tank Army was destroyed in fighting at the gates of Praga in early August, and the front stabilised for months.
The German side had about 25,000 men in the city, many of them in second-line units, and brought in reinforcements including the Dirlewanger brigade and Kaminski's Russian brigade, which committed the worst atrocities of the fighting. The Wola massacre in the first week killed about 40,000 civilians in three days, under Hitler's direct order that Warsaw be razed and its population killed.
The insurgents held out with almost no external supply. The RAF and the USAAF dropped arms by parachute from August 13, mostly at night and from high altitude, and most of it fell into German hands. Soviet aircraft dropped some supplies in September. By late September the Home Army held a strip of the city a few hundred metres wide and was running out of water and ammunition.
The capitulation had one condition, that the fighters be treated as prisoners of war, and they were, which is unusual for this war and was the result of negotiation. Civilians were expelled. About 350,000 of them left, and the population of the city when the Red Army entered in January 1945 was about 1,000. Warsaw was rebuilt after the war, and the Old Town was reconstructed from Canaletto's eighteenth-century paintings.