A novel by Théophile Gautier, which he claimed to have had the idea for as a child; it is set in the time of Louis XIII, his and every sane person's favorite period (although perhaps we can forgive those who prefer the Good King Henry). The plot concerns a comically impoverished young nobleman, who, after a chance meeting with a troupe of comedians, decides, in spite of the social degradation this entails, to join them; conveniently, all Commedia characters are stock figures, most of which appear masked, and so the young man treads the boards in the character of Captain Fracasse, essentially an instance of that worthy figure Il Capitano. This mask enables the protagonist to avoid his noble blood and specific identity being found out — at least, theoretically it does; in practice of course much of the plot circles around avoiding such outcomes. The plot is also notable for the fact that the fairly frequent sword fights have a surprisingly low actual body count: assassins and duelists get chased off or simply stunned by superior swordsmanship rather than stabbed straight into Hell, as Dumas would have had it.
Extremely loath though I am to spoil a book, I do feel in this instance that I need to remark on the ending in a general way: the last few chapters of what has until that point been a fairly reasonable adventure novel are so preposterous as to undermine the reader's suspension of disbelief entirely. I am not enough of a scholar of Gautier to know whether this is deliberate, done for a kind of artistic effect, or a grave misjudgment; either way, I might recommend putting the book down immediately after the fight between Sigognac and Vallombreuse in chapter XVII, and going no further.