That film is one of the worst examples of making "historical" movies!
That film is supposed to be based on well-known novel by Alexander Dumas, but unfortunately that film has nothing in common with the book! Alexander Dumas would be shocked if he would see that movie!
Although the story told by Dumas is also not true, but it is good written and it is written to be a part of 17th century.
To learn more on "Iron Mask" look at that site for it under "Politics".

Leonardo di Caprio playes in that film two roles. He playes Louis XIV and his twin brother (who never existed in reality). Leonardo di Caprio is unfortunately unable to play such serious and such challenging role, as such of Sun King. So the whole film turnes into farce!
Changed storyline (in comparison with the Duma's book) doesn't make the film better. The most lauphable and embarrassing moment of the film is when Louis XIV learns, that he is the son of D'Artagnan! My God, that is so terrible!
Although the costumes are nice, and the film was filmed partly at the real locations; and there are also some good actors as Jeremy Irons, John Malkovich and Gerard Depardieu, I would never advice anybody to watch that movie! It is so poor!

So unfortunately I had to put that film in the same category, as other films you see listed on the top of that page, as these films are also "fiction". But if all other films listed there are just nice, charming and harmless interpretations of 17th century France, so that film is just a negative example of making historical films and playing the role of a king. Another unfortunate thing, is that the makers of that film supposed that the film is based on original story, what made many people, who are not that knowledgeble in history, believe that the storyline shows something true.

Leonardo DiCaprio (as Louis XIV and twin-brother)
Jeremy Irons
John Malkovich

Gabriel Byrne
Anne Parillaud

Edward Atterton