 Although the story is fictional, some of the details are based on  the life of Austrian Crown Prince Rudolf, only son of  Emperor Franz Josef (qv). The painting of the emperor which  Eisenheim creates is an actual portrait of Franz Josef. The bodies  of Rudolf and his mistress, the Baroness Mary Vetsera, were found at  his hunting lodge Mayerling on January 30, 1889 in what is now known  as the "Mayerling Incident". This was initially covered up by the  Imperial Family, creating controversy and mystery.