By August of 1942 reinforcements sent to assist Army Group B's drive on Stalingrad had transformed the German Sixth Army from a potent assembly of men and machines to the most powerful army in the world, with 22 divisions and supporting units under the command of General Friedrich Paulus. Facing the Sixth Army, and Fourth Panzer Army's seven German and four Romanian divisions, was a Soviet Stalingrad Front that had been decimated in July.
During the summer of 1942 Hitler and OKH had split Germany's Army Group South in two. Army Group A represented the linchpin of the German strategic effort. Army Group A's objectives included the Maikop oil fields (captured during August, albeit after being thoroughly demolished), the Grozny oil refineries, and the Baku oil fields. Together, these oil fields and refineries constituted the overwhelming majority of the Soviet Union's sources of oil.
On November 23,1942, and following the November 19, 1942 beginning of Operation Uranus, the spearheads from the Soviet Southwest and Stalingrad fronts, met at Kalach to Stalingrad’s west. They had cut off the entire German 6th Army and part of the 4th Panzer Army in a massive pocket. Following a belated and thwarted German relief effort the final role for the formerly proud and merciless 6th Army was to tie down the Soviet armies around Stalingrad as German Army Group A completed its withdrawal from the Caucusus.