Otto Wilhelm Rahn (18 February 1904—13 March 1939) was a German medievalist, born in Michelstadt, Germany, died in Söll (Kufstein, Tyrol) in Austria.
Montségur, the fortress of the Cathars in southwestern France
Rahn wrote two books linking Montségur and Cathars with the Holy Grail: Kreuzzug gegen den Gral (Crusade Towards the Grail) in 1933 and Luzifers Hofgesind (Lucifer's Court) in 1937. After the publication of his first book, Rahn's work came to the attention of Heinrich Himmler, the head of the SS, who was fascinated by the occult and had already initiated research in the south of France.
"Crusade Towards the Grail" by Rahn
On 13 March 1939 only 3 days before on the anniversary of the fall of Montségur, Rahn was found frozen to death on a mountainside near Söll (Kufstein, Tirol) in Austria. His death was officially ruled a suicide.
Rahn has been described as the inspiration behind the Indiana Jones film Raiders of the Lost Ark although neither George Lucas nor Steven Spielberg has ever mentioned anything about his having inspired the film.
Rahn has been the object of many rumours and strange stories, including that his death had been faked, although all such speculation has failed to be substantiated. He features as a character in the 2008 novel The Judas Apocalypse by Dan McNeil. He also figures in the "Berlin Noir" novel The Pale Criminal by Philip Kerr and Blood Lance by Craig Smith. In the Italian comic book Martin Mystère, Rahn fakes his death and joins the US secret service "Elsewhere". Richard Stanley, cult director of such films as Hardware and Dust Devil, also made a documentary about Rahn and his fixation on the Holy Grail called The Secret Glory in 2001.
Source inter alia: Wikipedia.