There is an element of substantial fact in this intriguing movie.

Rating: 8/10 (20 August 2006)

The Illusionist is one of the more memorable movies I have seen in 60 years of movie-going. I wo'nt bother commenting on the movie itself. What I have not seen in the fifty reviews, or so, I have read is any allusion to the historical realities of the movie. There are no spoilers below that I am aware of.
Franz Josef was the Austro-Hungarian emperor,1848-1916. His grandson was Rudolf (Leopold in the movie). Rudolf DID want to reform the empire. He also was a womanizer and SM oriented. His most infamous and tragic relationship,1899, was with Marie Vetsera,18 years old. After a liaison of 9 months that went to Mayerling, the imperial hunting lodge. They were later found dead. Murder-suicide, double murder, mutual suicide. No one knows.
To this day, the facts of Mayerling are disputed. But, as with JFK's assassination, Mayerling raises all the "what-ifs"? If Rudolf had remained as heir to the throne, would his liberal reign have prevented WWI, etc.?
I was not surprised that the few people I talked with in the theatre, knew nothing of the historical setting of the movie. I was disappointed that none of the reviewers, including NYT, etc. did not refer to the real Rudolf. The few people I talked to in the theatre found my info worthwhile, and film-enhancing.
Yes, I am a retired History teacher.