The uprising was part of larger AK operation codenamed Operation Tempest. It was intended as both direct operation against German occupiers as well as political manifestation of influences of Polish Government-in-Exile, sparked by fear, that in the aftermath of the war allies would omit the legal London-based government (Soviet Union was not recognising Government-in-Exile and it was clear that Poland will be liberated by Red Army). The operation came to a halt due to Soviet politics of collaboration with Home Army only on a tactical level and then shooting or sending the Home Army soldiers to Siberia. There were many different opinions as to what should be the polish response, but it became clear that the all-national Uprising would be too costly and would end the same way as Lwow Uprising and Wilno Uprising ended. However, on July 29 1944 Soviet Radio Moscow called Poles in Warsaw to revolt. The underground civil and military authorities decided that it would be better to start the Uprising in Warsaw on a fixed date than to let separate groups start it on their own. There was also a huge pression to prove the Soviet propaganda stating that the Poles do not fight wrong. Moreover, for the last several days before the start of the Uprising, large german units were retreating westwards through Warsaw. This gave an impression that the city will be abandoned soon.
There were approximately 50.000 AK soldiers in Warsaw, of which 10% were properly armed, almost exclusively in hand arms. But order of starting uprising reached only 23,000 of them in time, mostly due to organisational problems.
18,000 of them were killed, 8,000-25,000 were heavily wounded, about 15,000 went into captivity. About 180,000-250,000 Polish civilians died as well, mostly as result of mass-executions - e.g after taking Wola (one of Warsaw districts) German soldiers executed approximately 40,000 civilian inhabitants.
Before Warsaw uprising it is believed that some 25,000 Jews were hiding in Warsaw. Vast majority of them died together with other Polish civilians. Many Jews (maybe as many as 1000), including those released by AK from Warsaw concentration camp (Gęsiówka), joined the Home Army.
Initial German garrison was about 20,000 ill-equipped soldiers, not enough to break through Polish lines, 'though there were at least 90,000 soldiers in the area at the start of hostilities. However, when the Uprising started, Heinrich Himmler ordered the city to be recaptured and burnt to the ground, probably for ideological reasons. By mid-September German troops were reinforced up to 50,000 men under SS general Erich von Bach-Zelewski. German losses were about 10,000-17,000 killed, 6,000 MIA and 9,000 wounded plus 300 armoured cars and tanks.
Until half of September Germans were shooting in place all caught insurgents. Main protagonists of the drama were Oskar Dirlewanger and Bronislaw Kaminski, who commited the most cruel attrocities. After von dem Bachs arrived to Warsaw (September 7), it became clear that attrocities only stiffen the resistance and that some political solution should be found due to small forces at the disposal of german commander. The basic idea was to gain a significant victory to show the Home Army the futility of further fight and make them surrender. This did not succeed, but from the end of September on, some of the captured polish soldiers were treated like PoWs.
After the uprising Germans systematically razed most of Warsaw to the ground. 85% of buildings were destroyed: 25% as result of uprising, 35% as result of systematical German actions after uprising, the rest as result of ealier Warsaw ghetto uprising and other fightings including September 1939 campaign.
Controversial is role of Soviet Red Army, which stood on the other bank of Vistula River, and who haven't allowed pilots from RAF and Polish Airforces to land on Soviet landings. After the initial radio and leaflet propaganda campaign, the Moscow-backed Wanda radio station remained silent until the very end of the fights. It has been argued that the Soviets deliberately allowed the Germans defeat the AK in order to eliminate a force in Poland which would oppose the communist puppet government which the Soviets planned to instal in Poland.