The history of Hapkido is the subject of some controversy. Some say that Hapkido was founded by Yong Sul Choi who from 1919 to the beginning of World War II, had studied Daito Ryu AikiJu-Jitsu in Japan. However, some claim that Choi's Daito Ryu training was limited to simply attending seminars.. Until the 1960's, Hapkido was known by various names: Yu Kwon Sool, Yu-Sool, Ho Shin Sool, and Bi Sool.
Ji, Han Jae is considered by some to be the father and founder of modern Hapkido. Ji started his physical training under Master Choi, Yong Sool (Sul) as a teenager in 1953. Choi taught Bok Suh Yu Sool, the Korean version of Daito Ryu AikiJu-Jitsu. At this time, certain Korean kicks and punches were combined and the name expanded to indicate the broadened art form called Korean Hap Ki Yu Kwon Sool.
Ji, Han Jae opened his first Yu Kwon Sool Hap Ki school one year after he began training under Choi with an agreed affiliation with him. Ji left Choi in 1956 to form his own organization, shortening the long name to Hapkido. Ji immigrated to the United States in the 60's and continues to teach Hapkido today.
Hapkido closely parallels (and is sometimes confused with) Aikido and is a complete system of self-defense using striking, kicking and grappling techniques. Hapkido and Aikido both have significant similarities to Daito Ryu AikiJu-Jitsu.
All Hapkido techniques are used for their practical self-defense purposes.Since the style is predominately defensive, a practitioner generally allows an attacker to make the first move, thereby committing him or herself. Originally a grappling and throwing art, it now includes a variety of strikes and kicks. Hapkido was introduced in the United States in the 1960s. The style became popular after the motion picture Billy Jack featured Hapkido in its fight scenes, realistically choreographed by Bong Soo Han, and it has grown in popularity since. In the 1970's and 80's Hapkido was taught as the style of choice to elite South Korean armed forces units.