What was the codename for the Soviet offensive that encircled the German 6th Army at Stalingrad?

The Soviet offensive that encircled the German 6th Army at Stalingrad was Operation Uranus. Launched on 19 November 1942, it attacked the German army's exposed flanks north and south of the city, where Romanian forces held much of the defensive line. The Soviets avoided striking directly into the hardest fighting in central Stalingrad.

The offensive used a double-envelopment plan. Southwestern and Don Front forces broke through near the Don River to the west, while the Stalingrad Front attacked from the south. Their armored spearheads met near Kalach-on-Don on 23 November, sealing the encirclement of German and allied Axis troops inside the Stalingrad area.

The trapped force included the German 6th Army, elements of the 4th Panzer Army, and Romanian and other Axis units. Adolf Hitler ordered the 6th Army to hold its position instead of breaking out, while the Luftwaffe attempted an airlift that could not provide enough supplies. Operation Uranus is often confused with Operation Mars, a separate Soviet offensive against Army Group Center, or Operation Saturn, the later plan aimed at wider Axis forces.