When the French stormed the Bastille in Paris during the Revolution in 1789, they found an entry referring to a prisoner as "the Man in the Iron Mask". From speculation about the identity of the person in the mask comes forth The Man in the Iron Mask, which is loosely based on the novel by Alexandre Dumas.
The year is 1660, and the French populace are starving, thanks to their cruel cold-blooded King Louis XIV (Leonardo DiCaprio). The Musketeers who served his father have now all gone their separate ways: Athos (John Malkovich) is devoted to the career and welfare of his son Raoul (Peter Sarsgaard); Porthos (Gerard Depardieu) is drinking wine and making merry even as his age begins to have its impact on his lifestyle; Aramis (Jeremy Irons) is now the leader of the Jesuits that have allied against the tyranny of Louis XIV; and D'Artagnan (Gabriel Byrne) remains loyal to the new King and is the Captain of the Musketeers.
There are various slight references to the political situation here, from the notion of the divine rule of Kings and the arrogance that stems from maintaining such a notion to distinctions of class, but unfortunately none of it is explored. The main reason the Musketeers rebel against the King is because Athos' son Raoul dies after being sent to the front to fight at Louis' orders.
Aramis concocts a plan to de-throne King Louis, by replacing him with a doppelganger. This involves rescuing the prisoner in the iron mask, Louis' Twin Philippe, who was imprisoned so he could not be a threat to Louis' power. This sets up a conflict between D'Artagnan and the three Musketeers, the Queen Mother, and Louis himself as he finds his loyalties divided. This is the most interesting aspect of the movie, but it comes too late.
DiCaprio presents a mixed performances in his "double acting" roles as Louis and Philippe. While the change of character is convincing (especially when Philippe's mask is removed), I think it could've been done better. The problem with DiCaprio, more than the acting, is in the delivery of the dialogue, the same problem which plagued him in Baz Luhrmann's Romeo and Juliet. The show is stolen by the actors playing the Musketeer characters, Irons, Depardieu, Malkovich, and Byrne. The mixing of accents (American, British, French) doesn't work well, but the costume and set design are well done, though not in the same class as Titanic.
While this movie could be considered slow and plodding at times, I personally found it to be a good time killer. There is very little suspense except in figuring out exactly how the switch between Philippe and King Louis will be made, but the outcome is inevitable. The Muskeeters are as much super heroes as Superman or Batman or Spawn, and it's worth checking out The Man in the Iron Mask to see how their saga ends, but then again, you might be better off reading the book.