The German Army Group South was a Wehrmacht’s large military structure, which was composed of three or more field armies. It fiercely fought in the Polish Campaign in September 1939, and on the Eastern Front from June 22, 1941, taking part in Operation Barbarossa, during World War II. In the German invasion of Poland, it was commanded by Gerd von Rundstedt, being composed of three field armies: the 14th Army, commanded by Wilhelm List; the 10th Army, under Walter von Reichenau; and the 8th Army led by Johannes Blaskowitz.
For the invasion of the Soviet Union, Army Group South was composed of the 17th Army, under Carl Heinrich von Stülpnagel, the 11th Army, under Eugen Ritter von Schobert, the 6th Army, led by Walther von Reichenau, 1st Panzer Group, commanded by Ewald von Kleist, and Luftflotte 4 (Air Fleet 4), which provided fire support to the ground forces. Until December 1941, it was also under the command of Gerd von Rundstedt, who was replaced by General Walther von Reichenau. Reinforced by the Romanian 3rd and 4th Armies, Army Group South invaded Ukraine and captured its capital, Kiev, as it encircled 600,000 Russian troops.
By mid 1942, it had been reorganized into Army Group A and Army Group B to conduct Operation Fall Blau to seize the Baku oil fields in the south. Between November 1942 and January 1943, the German 6th Army was destroyed in the Battle of Stalingrad during operation Fall Blau; however, it would be reorganized later on.
By 1944, Army Group South was made up of the German 8th and 6th armies and the Hungarian 2nd and 3rd Armies, under the command of Johannes Friessner.