Army Groups and Armies

The largest field formation in the German Army was known as an Army Group, which was a headquarters controlling two or more Armies. 'An Army Group was customarily commanded by a Feldmarschall (five-star general), or more rarely by a Generaloberst (four star general). An Army might be commanded by a Feldmarschall, a Generaloberst, or a General (three-star general).

At the beginning of the war, an Army Group Headquarters was usually formed for a particular campaign or occupational theater. During actual operations, the principal purpose of an Army Group was to exercise operational command over the Armies subordinated to it. It had at first a relatively small staff devoted purely to operational matters. As the war progressed, administrative functions were added and its staff increased.

An Army Headquarters was a more permanent command framework. In addition to its operational and tactical control of subordinate units, the Army was the top field headquarters for matters of administration, supply, and other functions. The size and structure of an Army Headquarters varied to a considerable extent. All headquarters were, however, organized according to a uniform system and consisted basically of a commanding officer assisted by a staff. The staffs of corps and higher headquarters were headed by a chief of staff. At all German headquarters, the staff officer in charge of operations was known as " la," the chief supply officer as " Ib," and the chief intelligence officer as " Ic."

During war time the operational area of the Army (Heeres) was divided into various segments. The operational area of an army (Armee) consisted of the combat zone and an army rear area. The operational area of an army group consisted of the operational areas of the armies under it and an army group rear area. The boundaries of the army group rear area coincided with the boundaries of the army rear areas and extended to the territory under civil administration of the Reich, such as the Commissariat Ostland in the east.