BERTHIER, Louis Alexandre (bare-te-r), prince of Wagram, French soldier, born in Versailles, 20 November 1753; died in Bamberg, 1 June 1815. He was educated as a soldier by his father, chief of topographical engineers under Louis XVI., and went into active service first as a staff-lieutenant, and afterward as a captain of dragoons, with which latter rank he came to America under Lafayette, and served during the war for independence, 1778-'82. Of this period of his life little is known. On his return to France he served the royal family until the revolution, when his talents made themselves felt and he became one of Bonaparte's generals of division, and subsequently his chief of staff, the most confidential of all positions for a military aide. tie followed the fortunes of Napoleon to the last, and was without a peer in his special line of staff duty. He is said to have been murdered by six men in masks; but some doubt has been thrown upon this story. His memoirs were published in Paris (1826).