Arnaud, the Marquis de Castelbajac competed in rapid-fire pistol shooting at the 1924 Paris Olympics. Marquis de Castelbajac graduated from l'Ãcole SpÃ©ciale Militaire de St-Cyr, and began a military career. He served in World War I from 1914-18, and was known as the co-inventor of the machine gun. In sport shooting, he won eight World Championship medals in team free pistol, with bronzes in 1905, 1907-08, and 1928-29; and silvers in 1912, 1924, and 1931.
Arnaud was the 11th Marquis de Castelbajac, from a long line of French nobility. His grandson Jean-Charles, also the Marquis de Castelbajac, became a prominent fashion designer, who designed creations for Madonna and supermodel Helena Christensen, among his many famous international clients.