The Reichsluftschutzbund, or National Air Raid Protection League, was formed
on April 29th, 1933. Initially, the RLB was a voluntary organization staffed
by hundreds of thousands of volunteers across Germany, but on March 13th,
1935, its volunteer status was removed and membership in the RLB became
obligatory for nearly all Germans. In 1938 its membership reached nearly
13 million, and in the spring of 1943, 22 million.
The RLB was organized into 15 Landesgruppen, each divided into Untergruppen, Ortsgruppen, and finally into Reviere (wards or precincts). It was initially formed in 1933 by a joint effort from NSDAP, Wehrmacht, and most importantly, the Luftwaffe, although up to 1940 it was considered seperate from the Air Force even though the German Air Ministry oversaw all RLB functions. In 1940 the RLB was formally taken over by the Luftwaffe, although it still served in its previous role and didn't outwardly change drastically and continued to operate as a dedicated civil defense organization.
Prior to 1942, the RLB was subdivided into two main areas, the Selbschutz - the Self-Protection Service, and the Erweiterter-Selbschutz - the Extended Self-Protection service. The Selbschutz was created for the local protection of regular citizens and families from air raids and attacks, and was based on a warden and fire-guard system designed to be the first line of defense in such situations. Its central duties were in equipping air raid shelters and the performance of fire-guard duties under the control of individual House Wardens for each home. Each block of residential homes in larger German cities and towns was to be in turn looked over by a Block Warden. Block Warden were in control of a number of streets, and in turn were looked over by a Ward Protection Leader. The overall function was similar to other European and American civilian air raid warning and assistance organizations, with roof spoters, individual home, block and ward services, and extenisve air raid shelters.
The Extended Self-Protection Service was established to watch over those institutions, buildings, offices, etc, that were not large enough or important enough to be provided with their own Work Air Raid Protection Service units known as the Werkluftschutzdienst. Extended Self-Protection units were formed from individuals that worked in the buildings in question, and served much like the regular Self-Protection service units mentioned above.
Both the Self-Protection units and the Extended Self-Protection units operated on a purely passive, reactionary basis. They went into action in response to air raids and attacks and reacted to the situations brought about by them. They didn't take part in offensive or defensive measures against the attacks in any way, leaving that to the main line anti-aircraft units of the Luftwaffe, and the various related units and organizations that agumented the extenisve German air defense system, the differance being that of air defense versus air raid protection, the latter being the function of the RLB and the Selbschutz services.
Other than the above mentioned services, the main burded of air raid protection was taken on by the many air protection related formations under the control of the German police, namely, the Luftschutzpolizei, which was formed in 1942 when it became obvious that the existing air raid protection services were no longer capable of dealing with the massive Allied raids on Germany and its occupied regions. The RLB, Luftschutzpolizei, Feuerschutzpolizei, and other related organizations such the Deutsche Rote Kreuz took on the brunt of the civil defense work in response to the increasingly devastating air attacks Germany experienced during WWII.