One of the ancient names of SunDo is the Way of Receiving Bar'k (Sun Energy) or BarkDolBup.
It is said that around the end of the last Ice Age, there was a group of people who traveled toward the East where the Sun rises every morning. They were looking for the source of warmth and life force which was thought to be brought by the sun. They yearned for the powerful energy of the sun and slowly began to practice intuitively to receive the energy of the sun (Way of Receiving Bark) by calmly facing the sun, humbly trying to receive the energy while changing postures to receive the energy to all parts of the body. The sun energy absorbing practice later developed into the complete system of SunDo. It is presumed that the SunDo system was fully structured during the Neolithic Age and continued to be a core element of the national education system until it was taken to the mountains.
In ancient times in Korea, some people, including the religious leaders or shamans, went to the mountains to attain the ability to communicate with Heaven. The sky, sun, moon, and stars were revealed as the vital force inherent in all beings, and it was thought that humans could get closer to Heaven (the universe, stars, sun) in the mountains. Their practice was naturally focused on breathing because the air was their connection with the sky, earth and human beings. They tried to breathe in more air and breathe harmoniously. They slowly learned to breathe through the skin, to circulate the inhaled Ki, and eventually attain full enlightenment and power. These teachings were orally transmitted in secret only to those who were mentally and physically prepared.
SunDo had flourished in the Northeast part of Asia where the ancient Korean nations were located until Buddhism and other religious teachings became the dominant culture. When SunDo flourished, it was said that all of the prominent kings, scholars, politicians and warriors were raised by SunDo practice. Over time, SunDo became less and less popular as people avoided the painstaking practice to develop the body and mind. As SunDo practice neared extinction in human society, the teachers of SunDo gathered a few students and retreated to the mountains to preserve the practice.
In the year 1967, a SunDo Grand Master, ChungSan, finally came down from the mountains after 20 years of SunDo practice. After hundreds of years of secluded practice, the grand masters in the mountains finally decided it was time to reveal the secrets of SunDo to the modern world for the benefit of all human kind.