The German UFO theories describe supposedly successful attempts to develop advanced aircraft or spacecraft before and during World War II, further asserting the post-war survival of these craft in secret underground bases in Antarctica, South America, or the United States, along with their creators.
In the first years of the Cold War, Western nations speculated that unusual sightings might stem from Soviet deployment of captured or reverse-engineered Nazi technology.
In World War II, the so-called "foo fighters", a variety of unusual and anomalous aerial phenomena, were witnessed by both Axis and Allied personnel.
Similar sentiments regarding German technology resurfaced during the 1947 flying disc craze after Kenneth Arnold's widely reported close encounter with nine crescent-shaped objects moving at a high velocity.
[17] In post-war Germany, Schriever drove supply trucks for the US Army but told newspaper reporters that delegates from foreign powers were constantly making him offers regarding his wartime projects.
Aeronautical engineer Roy Fedden remarked that the only craft that could approach the capabilities attributed to flying saucers were those being designed by the Germans towards the end of the war.
According to these theories and fictional stories, various potential code-names or sub-classifications of Nazi UFO craft such as Rundflugzeug, Feuerball, Diskus, Haunebu, Hauneburg-Gerät, Glocke, V7, Vril, Kugelblitz (not related to the self-propelled anti-aircraft gun of the same name), Andromeda-Gerät, Flugkreisel, Kugelwaffe, Jenseitsflugmaschine, and Reichsflugscheibe have all been referenced.
Accounts appeared as early as 1950, likely inspired by historical German development of specialized engines such as Viktor Schauberger's "Repulsine" around the time of World War II.
Elements of these claims have been incorporated into various works of fictional and purportedly non-fictional media, including video games and documentaries, often mixed in with more substantiated information.
German UFO literature very often conforms largely to documented history on the following points: Le Matin des Magiciens ("The Morning of the Magicians"), a 1960 book by Louis Pauwels and Jacques Bergier, made many spectacular claims about the Vril Society of Berlin.
[22] Several years later, writers, including Jan van Helsing,[23][24] Norbert-Jürgen Ratthofer,[25] and Vladimir Terziski, have built on their work, connecting the Vril Society with UFOs.
When German Holocaust denier Ernst Zündel started Samisdat Publishers in the 1970s, he initially catered to the UFOlogy community, which was then at its peak of public acceptance.