In a lead role in Operation Undertone, its Seventh Army fought its way across the Rhine into Germany, captured Nuremberg and then Munich.

[3] The Sixth Army Group was originally created in Corsica, France (specifically activated on 29 July 1944[4]) as "Advanced Allied Force HQ", a special headquarters within AFHQ (the headquarters of Henry Maitland Wilson, the Supreme Commander Mediterranean Theatre) commanded by Lieutenant General Jacob L. Devers.

[4] Devers' headquarters remained subordinate to AFHQ during the invasion and in the weeks immediately afterwards while operational control of the troops on the ground resided with Patch until his forces linked near Dijon, France, with Twelfth United States Army Group's Third Army advancing from the west after breaking out of the Normandy beachhead.

[8] In late 1944 and early 1945 the Sixth Army Group was involved in fierce fighting in the Alsace repelling the German advance during Operation Nordwind and subsequent pitched engagements closing off the Colmar Pocket.

Order of battle shifted frequently in the Sixth Army Group, but accelerated dramatically during its late-war push through southern Bavaria into the Austrian Alps to head off German establishment of a National Redoubt and close off passes to Nazi escape.