French prince imperial, the only son of Napoleon III by Empress Eugénie.

He was a delicate boy, but when the Franco-German War of 1870 broke out his mother sent him to the army. After the first defeats he had to flee from France with the Empress and settled in England at Chislehurst, completing his military education at Woolwich. On his father's death (Jan. 9, 1873) the Bonapartists proclaimed him Napoleon IV, and he became the official pretender. The Bonapartist leaders thought that he should win his crown by military prestige, and he was persuaded to attach himself as a volunteer to the British expedition to Zululand in February 1879. While out on reconnaissance with a few troopers he was surprised by Zulus and killed at Ulundi. His body was brought back to England and buried at Chislehurst.

After attending military school at Châlons, France, Louis accompanied Napoleon on the Italian campaign of 1796–97 and acted as his aide-de-camp in Egypt in 1798–99. In 1802 Napoleon as first consul married him to Joséphine's daughter Hortense de Beauharnais (Hortense); the forced union led to deplorable results springing from Louis's violent jealousy of his wife and his growing resentment toward Napoleon for not allowing the couple to divorce. (Their youngest child, Charles-Louis-Napoléon Bonaparte, survived to become Napoleon III.) In 1804 Louis was raised to the rank of general and the following year became governor of Paris.

Napoleon proclaimed Louis king of Holland on July 5, 1806. From the first, the emperor reproached him for being too easy on his subjects. By 1809 Napoleon was considering annexing Holland in order to arrest the trade the Dutch secretly conducted with England. In 1810, failing to negotiate successfully with either England or Louis, the emperor dispatched French troops against the Dutch capital. Louis abdicated and fled his kingdom, which on July 9 Napoleon annexed to France.

Styling himself the comte de Saint-Leu, Louis lived for some time in Bohemia, Austria, and Switzerland. He spent his later life in Italy, largely occupied with literary pursuits. He wrote Documents historiques et réflexions sur le gouvernement de la Hollande, 3 vol. (1820; Historical Documents and Reflections on the Government of Holland, 1820), and two partial works, Marie, ou les peines de l'amour, 2 vol. (1812; Maria; or, the Hollanders, 1815), and Le Retour (1846; “The Return”).