On 1 July 1938, the "Air Defense Command
Essen" () staff was formed, later redesignated "Air Defense Command
Düsseldorf" (). On 1 August 1939, this Air Defense Command received its ordinal number 4, becoming "4th Air Defense Command" (). The initial head of the staff was Kurt Steudemann, who was replaced on 31 October 1939 by Otto-Wilhelm von Renz. It was initially the only air defense command in the
Ruhr area. It was assigned to Luftgau VI, headquartered at
Münster, along with
7th Flak Division (created in March 1940) in
Cologne. On 1 September 1941, the 4th Air Defense Command was officially designated the "4th Flak Division" and initially remained headquartered at Düsseldorf, though its HQ was subsequently redeployed in July 1942 to
Ratingen. In 1945, the 4th Flak Division was used in ground-level combat on the Western Front, along the Rhine river. On 18 April 1945, the 4th Flak Division surrendered as part of the
Ruhr pocket. == References ==