As the Red Army approached Warsaw (July 29–30, 1944), Soviet authorities, promising aid, encouraged the Polish underground there to stage an uprising against the Germans. However, the Polish underground, known as the Home Army, was anxious because the Soviet Union had already assumed direct control of eastern Poland and had sponsored the formation of the Polish Committee of National Liberation to administer the remainder of Soviet-occupied Polish territory. Hoping to gain control of Warsaw before the Red Army could “liberate” it, the Home Army followed the Soviet suggestion to revolt.Commanded by General Tadeusz Bór-Komorowski, the Warsaw corps of 50,000 troops attacked the relatively weak German force on August 1 and within three days gained control of most of the city. The Germans sent in reinforcements, however, and forced the Poles into a defensive position, bombarding them with air and artillery attacks for the next 63 days.Meanwhile, the Red Army, which had been detained during the first days of the insurrection by a German assault, occupied a position at Praga, a suburb across the Vistula River from Warsaw, and remained idle. In addition, the Soviet government refused to allow the western Allies to use Soviet air bases to airlift supplies to the beleaguered Poles.