In June 1682, Vermandois was exiled to
Normandy. Others were exiled, too, including the Prince de
La Roche-sur-Yon (nephew of the Prince de Condé), the Prince de Turenne, the Marquis de Créquy, the Chevalier de Sainte-Maure, the
Chevalier de Mailly, and the Comte de Roucy. Hoping to mend the relationship between father and son, his aunt
Madame suggested that he be sent as a
soldier to
Flanders, then under French occupation. Agreeing with his sister-in-law, the king sent his son to the
Siege of
Kortrijk, where Vermandois soon fell
ill. He was advised by a doctor that he should return to
Lille and recover, but, desperate for his father's love, he remained on the
battlefield. He died in Flanders on 18 November 1683, and was buried in the
Arras Cathedral. His aunt and sister greatly mourned his death, while his father reportedly did not shed a tear. His mother, by then a
Carmelite nun under the name of
Sœur Louise de la Miséricordie ("Sister Louise of
Grace"), was still obsessed with the
sin of her affair with the king and said upon hearing the news of her son's death, "I ought to weep for his birth far more than his death". In 1745, an anonymous writer published a book in Amsterdam, ''Mémoires pour servir à l'Histoire de la Perse'', romanticising life at the French Court in the form of Persian history. Members of the royal family and locations were given fictitious Persian names, and their key was published in the book's third edition (1759). In this tale, Vermandois is alleged to have struck his half-brother,
Louis, Grand Dauphin, causing the King to banish him to life imprisonment, first at the
Île Sainte-Marguerite and later at the
Bastille, where he was made to wear a mask whenever he was to be seen or attended to, when sick or in other circumstances, and would later become known as the legendary
Man in the Iron Mask. In reality, there are no historical records of gossip confirming that Vermandois ever struck the Grand Dauphin, or been imprisoned. Furthermore, in 1769 a Jesuit named
Henri Griffet, who had been chaplain of the Bastille from 1745, published a book with unquestionable evidence that the prisoner known as the Man in the Iron Mask had died at the Bastille on Monday, 19 November 1703. ==Ancestry==