In autumn, Soviet General Georgi Konstantinovich Zhukov, responsible for strategic planning in the Stalingrad region, concentrated Soviet forces in the steppes north and south of the city. The German northern flank was particularly vulnerable, as it was defended by Hungarian and Romanian units with inferior equipment and low morale. Zhukov's plan was to keep the Germans south in the city, break through the broad, weakly defended German flanks, and surround the Germans inside Stalingrad. This operation, whose code name was Uranus, was launched on November 19, 1942, at the same time as the "Mars" operation, which was directed towards the center.
Soviet units attacked under the command of General Nikolai Vatutin. They were composed of three complete armies, the 1st Guards, the 5th Tank Regiment and the 21st Army, including a total of eighteen infantry divisions, eight tank brigades, two motorized brigades , six cavalry divisions and an anti-tank brigade. Romanian troops continued to request reinforcements without result. Outstretched, outnumbered and ill-equipped, the Romanian 3rd Army, which held the northern flank of the German 6th Army, was shattered after a near-miraculous one-day defense.
On November 22, the two pincers of the pincers met at Kalach, completing the encirclement of Stalingrad.