Man in the Iron Mask in the mask. It has even been suggested that he was one of the other famous contemporary prisoners being held at Pignerol at the same time as Dauger. Voltaire claimed that the prisoner was a son of Anne of Austria and Cardinal Mazarin, and therefore an illegitimate half-brother of King Louis XIV. However, the sincerity of this claim is uncertain. In his history essay "Le Masque de fer", French novelist Marcel Pagnol, supporting his theory in particular on the circumstances of King Louis XIV's birth, claims that the Man in the Iron mask was indeed a twin but born second,
Man in the Iron Mask jailers took – created significant interest in his story and gave birth to many legends. Many theories exist and several books have been written about the case. Some were presented after the existence of the letters was widely known. Still later commentators have presented their own theories, possibly based on embellished versions of the original tale. Theories about his identity popular during his time included that he was a Marshal of France; the English Henry Cromwell, son of Oliver Cromwell; or François, Duke of Beaufort. Later, many people such as Voltaire and Alexandre Dumas suggested other theories about the man