Ji Han-Jae (Hangul: 지한재; Chi Hon-tsoi) was born in Andong, Gyeongsangbuk-do, South Korea in 1936. He is one of the highest ranking hapkido instructors in the world and founder of Sin Moo Hapkido.

He began his martial arts training in 1949 under the direction of Choi Yong-Sool (Hangul: 최용술), and was Dan No 14 under Choi. Ji trained with Choi Yong-Sool until 1956 when he moved to Seoul in order to open a school of self-defence in the nation's capital. Ji Han-Jae trained in the ancient methods of the Korean martial arts, known as Sam Rang Do Tek Gi by a man named Taoist Lee. Though this man's identity can never be confirmed, it is believed that he trained Ji in meditation, the use of the Korean long staff "Jang-Bong (장봉; 長棒)", short staff "Dan-Bong (단봉; 短棒)", and the unique kicks of Sam Rang Do Tek Gi.

In 1959 Ji Han-Jae combined all of his martial arts knowledge together and began to teach hapkido.

Many people consider Ji Han Jae to be the founder of hapkido, while others will credit his teacher, Choi Yong-Sool, who referred to his art as "Yawara (Hangul: 야와라; 柔)" or "Yu Kwon Sul (Hangul: 유권술; 柔拳術)". It is commonly believed that it was Ji who first started using the name hapkido for the techniques he was teaching at that time. Seo Bok-Seob, the first student of Choi, however states in a 1980 interview that it was Jung Moo Kwan who first used the term to refer to the art as well as the symbol of the eagle to represent the art. Regardless, much the curriculum and techniques that we associate with hapkido today is heavily marked by changes that were implemented by Ji Han-Jae and his senior students.

Hwang In Shik (also Whang Ing-Sik, born September 13th, 1940) is one of the foremost Korean hapkido teachers today. A great popularizer of the art in Asia through his work in the Hong Kong based films of Bruce Lee, Jackie Chan and Angela Mao, he is known nevertheless as one the top teachers of the art and was eventually awarded a 10th degree black belt, the highest rank possible in the art, by the World Hapkido Association.

Born in Sunch'ŏn, north of Pyongyang in present day North Korea, Hwang In-Shik and his family moved to Seoul while he still a young child and it was there that he was first exposed to the martial arts, first to Tang Soo Do and then, when he was 13 years old, to the art of Korean hapkido.

Hwang identifies his teacher as Choi Yong Sul, the founder of the art. According to Kim Hyung Sang of the Ulchikwan dojang Hwang's first teacher was Kim Yong-Jin. Hwang In Shik achieved his black belt grading at age 16 and was sent shortly thereafter to the Korea Hapkido Association headquarters presided over by Ji Han Jae. A very important time in the history of the development of the art, many of the prime movers in hapkido today were his seniors there including Han Bong Soo, Kim Chong Sung and Myung Kwang-Sik. Hwang was known in particular at this time for his superlative kicking ability.

Bruce Lee (born Lee Jun-fan; 27 November 1940 – 20 July 1973) was a Chinese AmericanHong Kong actor,martial arts instructor, philosopher, film director, film producer, screenwriter, and founder of the Jeet Kune Do martial arts movement. He is widely considered by many commentators, critics, media and other martial artists to be the most influential martial artist and pop culture icon of the 20th Century. He is often credited with changing the way Asians were presented in American films.

Lee was born in San Francisco to parents of Hong Kong heritage but was raised in Hong Kong until his late teens. Lee returned to the United States at the age of 18 to claim his U.S. citizenship and receive his higher education. It was during this time that he began teaching martial arts, which soon led to film and television roles.

His Hong Kong and Hollywood-produced films elevated the traditional Hong Kong martial arts film to a new level of popularity and acclaim, and sparked a major surge of interest in Chinese martial arts in the West in the 1970s. The direction and tone of his films changed and influenced martial arts and martial arts films in Hong Kong and the rest of the world, as well. He is noted for his roles in five feature-length films: Lo Wei's The Big Boss (1971) and Fist of Fury (1972); Way of the Dragon (1972), directed and written by Lee; Warner Brothers' Enter the Dragon (1973) and The Game of Death (1978), both directed by Robert Clouse.