Each Luftkreis was led by a Höherer Fliegerkommandeur (Senior Air Commander) in charge of all aviation units within its area. These included, two or three Luftgaukommandos (administrative commands), a signals command, a medical battalion and a procurement and supply group. Their area of operations also included civilian airfields and Civil Air Defense. The following year, all the replacement battalions in that area also came under their control. In 1936, these were extended to regiment size or Fliegerersatzregimente. From 1935 to 1936, Flak units in the area also came under their command. Hermann Göring and Erhard Milch appointed retired army lieutenant generals to lead each Luftkreis. These were , and Leonhard Kaupisch. They were promoted to General der Flieger. A retired navy officer, Konrad Zander, was similarly promoted and put in charge of Luftkreis VI supporting the naval units. Two Luftwaffe officers, Colonel Hugo Sperrle and Major General were put in charge of the remaining two Luftkreise without being promoted. Operationally, the Luftwaffe organization underwent changes in July 1938. Luftkreise were consolidated into three Luftwaffengruppenkommandos (Airforce Group Commands). As a result, on 1 August 1938, Luftwaffenkommando Ostpreußen (Airforce Command East Prussia) replaced Luftkreis 1. This change also rendered the three digit Geschwader identifiers meaningless. From 1 November 1938, Geschwader identifiers were changed universally. The third digit of the Unit Identifier was replaced with the same digit as its parent Luftwaffengruppenkommando. For example, all units under Luftwaffengruppenkommando 1 (headquartered in Berlin), had the third digit of their identifiers replaced with a '1'. For units under Luftwaffengruppenkommando Ostpreußen, the third digit was replaced with a zero. By the end of April 1939, another Luftwaffengruppenkommando was added. All four Luftwaffengruppenkommando were renamed Luftflotte (Air Fleets). Geschwader under each Luftflotte, were re-numbered sequentially. Each Luftflotte received a batch of 25. For example, Luftflotte 1 Geschwader were numbered 0–25, Luftflotte 2 Geschwader became 26–50 and so on. Luftgaue Within the Air Ministry, for administration purposes, the Luftwaffe was organized into Luftgaue (Air Districts), based on the army's Wehrkreis ("military districts"). A Luftgau was responsible for all administrative activities, such as training, administration, maintenance, air defense, signals, recruitment and reserve personnel. The Generalmajor leading the Luftgau-kommando of each Luftgau reported to the Air Ministry. Those Luftgaue established within Germany were numbered non-consecutively with Roman numerals. Luftgau I (Königsberg) Luftgau II (Stettin) Luftgau III (Berlin) Luftgau IV (Dresden) Luftgau V (Stuttgart) Luftgau VI (Münster) Luftgau VII (Munich) Luftgau