He started learning taekwondo in his teens in Seoul. During the Korean War, he was an interpreter for the U.S. Air Force. Eventually he was drafted into the South Korean army.
He was a grandmaster of taekwondo who helped to popularize it in the US. He began teaching classes in 1956 in Texas as part of a military training program. In 1962 he opened a gym in Washington DC, where his students included members of Congress.