Lvov–Sandomierz Offensive
The Soviet units which reached the outskirts of Warsaw in the final days of July 1944 had advanced from the 1st Belorussian Front in Western Ukraine as part of the Lublin–Brest Offensive, between the Lvov–Sandomierz Offensive on its left and Operation Bagration on its right. These two flanking operations were colossal defeats for the German army and completely destroyed a large number of German formations. As a consequence, the Germans at this time were desperately trying to put together a new force to hold the line of the Vistula, the last major river barrier between the Red Army and Germany proper, rushing in units in various stages of readiness from all over Europe. These included many infantry units of poor quality, and 4–5 high quality Panzer Divisions in the 39th Panzer Corps and 4th SS Panzer Corps pulled from their refits.