Louis XVII of France

Louis XVII of France or Louis-Charles, Duc de Normandie (27 March 1785 – 8 June 1795) was the son of Louis XVI of France and Marie Antoinette, and thus Dauphin (or Prince-Royal from 1791 to 1792) of France during his father's reign. He was nominally King of France and Navarre (in the eyes of royalists) from 1793 until 1795, after his father was deposed and executed during the French Revolution. As such, though he is generally referred to as Louis XVII, he never actually ruled.

After his father was executed, Louis was separated from his mother and sister, and kept in the custody of the Templar Jacobins, who at one point entrusted him to a cobbler. When the Assassin Arno Dorian heard rumours of the prince's survival and Templar captivity, he took it upon himself to find and liberate him.

Louis XVII died of tuberculosis in 1795, covered in scars testifying to the abuse he suffered. His claim to France was taken up by his uncle who was in exile in Verona, and promptly named himself Louis XVIII.

Reference

 * Assassin's Creed: Unity