The five foot, 2 inches, gentle looking man called the "Human Atomic Bomb"- "Mighty Atom" - "Little Giant Killer" as a 12 year old boy in 1907 Liverpool England, made after school pocket money selling programmes at the Vaudeville Pavilion theatre. As a child Bill was a friend of great performers like the legendary Harry Houdini, Buffalo Bill Cody and Charlie Chaplin.  Most are unaware of the fact that it was Bill Underwood who was standing at Harry Houdini's side on McGill Campus in Montreal in 1926, when Harry recieved the punch to the stomach that would soon after end his life.   Periodically on the Vaudeville circuit Japanese Jiu-Jitsu experts would demonstrate their incredible abilities on the local stage. Crowds would be amazed while watching small Japanese men nightly throwing big muscle-men around the stage like rag dolls. Between acts backstage Bill developed a friendship with world famous Jiu-Jitsu experts Yukio Tani and Tara Maki and they began to teach him in a short period of time some of the basic techniques of their craft. Unbeknown to anyone, Bill was a prodigy in the making. With limited exposure to his instructors he began to develop and build immediately upon some of the techniques he had learned and evolved them into what would become a unique, improved system.

Bill then emmigrated to Canada, and in 1914 came back overseas with the Grenadier Guards of the Royal Montreal Regiment. He continued to develop his fighting system and extricated himself from numerous life and death situations during the war using his Combato. In full hand-to-hand fighting mode he escaped the Germans at Ypres on foot, following the first gas attack in April, 1915. The next year, he transferred to the Royal Flying Corps as a pilot and learned gunnery from Canada's Billy Bishop, and he became friends with Roy Brown - the man who shot down the Red Baron.