In mid-December 1942, after encircling the German Sixth Army at Stalingrad, Soviet forces in southern Russia began a series of offensive operations which continued unabated into February 1943. In these offensives the Soviet High Command attempted to smash German resistance and encircle the bulk of two German army groups. For two months the German forces struck back. In a well co-ordinated counterstroke they inflicted a major operational defeat on the Soviets and stabilized the front until the summer. The two-month period of Soviet offensive activity during the winter of 1942-1943 saw the Red Army test new operational and tactical techniques and experiment with forces and methods for conducting mobile armoured warfare. Through victory and defeat the Red Army learnt its lesson well. Out of this period, and the three month period of relative calm that followed, emerged the new Red Army, which would defeat blitzkreig at Kursk and would achieve two years of virtually uninterrupted battlefield success,culminating in their defeat of Nazi Germanu.