the capture of Rostov, july 1942, Hitler decided to split up Army Group South in two
smaller army groups.
Hitler's Directive #45
Army Group A :
Commanded by Generalfeldmarschall
Army Group B :
Generalfeldmarshall Maximilian Freiherr von Weichs.
Army Group A was ordered to
capture the Caucasus.
Army Group B was ordered to reach the Volga and capture Stalingrad and
German 6th Army was part of Army Group B