French army officer.
Entered the French service (1769). Second in command of the Saintonge regiment in 1780; served in America with Rochambeau. Maréchal de camp (1788). Deputy to the Estates General. Emigrated (c. 1790) and served in the princes’ army. Raised a regiment that served in Portugal (1797-1802). Returned to France (1814), where he was made a lieutenant-general and a peer of France.
Son of Charles-Eugène-Gabriel de La Croix and Gabrielle-Isabeau-Thérèse de Rosset de Fleury, marquis and marquise de Castries. Married Marie-Adrienne de Bonnières de Guines; three children. Married Elisa Coghlan; three children.