Having fought hard just to reach the outskirts of Stalingrad, the Axis forces found themselves embroiled in a protracted urban battle amid the ruins of a devastated city on the Volga. The Soviet Red Army was able to hold onto the city then mount a surprise winter counter-offensive known as Operation Uranus, which succeeded in encircling the German 6.Armee at Stalingrad. Despite a desperate German relief operation, the Red Army eventually crushed the 6.Armee and hurled the remnants of the German southern front back in disorder.