Battles of Rzhev
Soviet partisans had been disrupting the rear of Army Group Center (and the German 4th Army in particular). In January 1942, they were strengthened by Soviet Airborne Troops (the Vyazma airborne desant operation, part of the Battles of Rzhev). The Soviets hoped that the airborne troops and the partisans would be able to secure territory and disrupt the German logistics long enough for the Soviet offensive to reach them. However, the Red Army offensive involving the 33rd Army and the 1st Guards Cavalry Corps failed to advance far enough and the Germans were able to concentrate on destroying Soviet troops in the rear.