The Warsaw Uprising began with simultaneous coordinated attacks at 17:00 hours on August 1, 1944 (W-hour). The uprising was intended to last a few days until Soviet forces arrived; however, this never happened, and the Polish forces had to fight almost without any outside assistance. Initially the battle raged throughout most of Warsaw, but after a short time it became confined to districts in the West of the town. The key factor in the battle was the massive imbalance of weapons between the two sides. The German side was extremely well equipped whilst the Polish side had, initially, barely enough ammunition for a few days. The policy of one bullet, one German allowed the Polish fighters to sustain the uprising for many weeks at the cost of their own lives. Some areas fought for a full 63 days before an agreed capitulation took place. The losses on the Polish side amounted to 18,000 soldiers killed, 25,000 wounded and over 250,000 civilians killed; those on the German side amounted to over 17,000 soldiers killed and 9,000 wounded.
Although Stalingrad had already shown the level of danger which a city can pose to armies which fight within it and the importance of local support to armies, the Warsaw uprising was probably the first demonstration that in an urban terrain, a vastly under-equipped force supported by the civilian population can hold its own against far better equipped professional soldiers— though at the cost of vast sacrifices on the part of the city's residents.
"W-hour" (from the Polish wybuch, "outbreak"[1]), the moment of the start of the uprising, had been rescheduled for 1 August at 1700 during a briefing on 31 July around 1730. The change of "W-hour" from 2400 (in earlier plans) to 1700 proved to be a costly strategic decision, reducing the chance of surprising the Germans, especially since many of the Polish partisans were not trained for prolonged day fighting. The order to start the uprising did not reach all of the units (around 23,000 personnel) due to the technological and logistic limitations of the underground movement.
Fighting broke out before the "W-hour" (scheduled for 1700) in several places where German units encountered organising Polish forces: around 1400 on Żoliborz, 1500 on Czerniaków, 1600 around Plac Napoleona, Hale Mirowskie, Plac Kercelego marketplace, Okopowa street and Mokotów.