A review of the legends and the realities.
Yes, there was a prisoner kept masked -- velvet, it seems, not iron. But things expanded from there. From Voltaire's hints, where he points out with great portentousness but, unfortunately no accuracy, that no one prominent vanished the year the man was arrested, that lead to the most common story, the twin of Louis XIV -- not, as it turns out, plausible, because all accounts agreed that the man in the mask was tall, and Louis XIV was, in fact, rather short. There is even a story that the man married the governor's daughter, and the Bonapartes were descended from the union.
Some of the others include an Italian involved in certain intrigues (the mask is credited to an Italian custom of wearing them to protect the face from teh sun), a princess (Louis XIV was substituted for her so Louis XIII would have an heir -- this theory comes from supporters of his brother Philippe's descendants, who would then be the rightful heir), an illegitimate son of Anne of Austria, an illegitimate son of Louis XIV, an illegitimate son of Charles II, the man that a secret society wanted to make king (kept alive so they would not go to a new candidate), and more.
His own theory was the prisoner was as obscure as he seemed from other evidence, and the drama was done by the prison governor to make his position look important.
It really is hard to reconcile the obsessive care taken with the prisoner with the menial treatment he also got.
Also touches on a lot of related topics, like prison and the justice system. Useful for anyone who wants to steal a melodramatic plot.