Guillaume Apollinaire
Two years after being wounded in World War I, Apollinaire died in the Spanish flu pandemic of 1918; he was 38.
Le Secret du Masque de fer
In the "Questions sur l'Encyclopédie" (1770), he declares that wearing the mask was enforced, including during medical examinations, for fear that ""an overly striking resemblance […] would be recognized"" and quotes the apothecary of the Bastille's account, to whom the prisoner is thought to have told his age shortly before his death, saying he was ""around sixty years old"". It is noticeable that the death certificate states a younger prisoner of ""forty-five years old or thereabouts."" Voltaire also wonders about the Italian name he was given, most probably referring to the death certificate.