Michał Owczarek has a more detailed look at the background:
By mid-1944, the German army was beginning to collapse partly due to spectacular Soviet victories on the Eastern Front, which in consequence brought the Red Army to the very gates of Warsaw.
Poland’s underground Home Army had a dilemma of whether to fight as command staff was riven on the matter.
Following a vote passed by a fine margin, the outbreak of the Warsaw Uprising, the so-called "W Hour," was set for 5 p.m. on August 1.
Overall, some 50,000 freedom fighters stood up against the Germans, many of whom eagerly awaited the order to rise up.
"Within minutes, Polish flags appeared as if out of nowhere, and the streets of Warsaw were swept up in a spontaneous wave of enthusiasm that grew stronger by the minute," insurgent Władysław Bartoszewski later recalled.
"People began building barricades—overturning trams, tearing up paving stones, and in a kind of euphoric frenzy, tossing furniture from their windows to reinforce the barricades meant to block potential German assaults," he said.
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