Emperor of the French, the style given by the Bonapartists to the son of Napoleon Napoleon Francis Joseph Charles, duke of Reichstadt (q.v.). The fact that in 1814, by Napoleon I.'s abdication in his favour, the king of Rome (as he was then styled) became for a few days titular emperor "by the will of the people," was held by Prince Louis Napoleon to justify his own assumption of the style of Napoleon III. which, as seeming to involve a dynastic claim, gave such offence to the legitimist powers, notably the emperor Nicholas I. of Russia.