Based on his training in boxing, wrestling, savate, early Judo at the Kodokan in Tokyo, and fights he was involved in during his police work, Fairbairn began to develop his own system of hand to hand combat, calling it "Defendu".
In the wider sense, it includes all stand-up combat sports that allow both punching and kicking, including Savate, Muay Thai, Indian boxing, Burmese boxing, Sanda, styles of Karate, etc.