Rex Applegate was an American military officer who worked for the Office of Strategic Services, where he trained Allied special forces personnel in close-quarters combat during World War II. He held the rank of colonel.

Lieutenant Colonel William Ewart Fairbairn was a British soldier and police officer. He developed hand-to-hand combat methods for the Shanghai Police during the interwar period, as well as for the Allied special forces during World War II. He created his own fighting system known as Defendu. Notably, this included innovative pistol shooting techniques and the development of the Fairbairn–Sykes fighting knife.