In 1122 the uncle of the Shang King of China, Ki-Ja, escaped the overthrow Shang Dynasty and migrated to Korea with 5000 followers. According to the legend, after reigning for 1,211 years, Dan-Gun fled from the Ki-Ja forces to the town of Mun-Wha, resumed his spirit form, and disappeared from the earth. The shrine to the "Trinity" in Mun-Wha today contains his 410-foot circumference "grave." The Ki-Ja assumed the rule of Korea from 1122 B.C. to 193 B.C., teaching the people Chinese culture in the form of letters, reading, writing, medicine, and art.
After the Silla unification of Korea, the myth of Dan Gun became widely respected. The Koryo dynasty viewed Dan-gun as the sole founder of the Korean kingdom and used the legend to demonstrate Korean superiority over the Mongolian tribes who had invaded and conquered Korea several times. By maintaining the Korean culture, the myth of Dan Gun played an important role in protecting Korean from invasion for several thousand years. October 3rd is celebrated as a national holiday, commemorating the founding father, Dan Gun.
In 1909, the legend of Dan-Gun again increased in popularity in the form of the Tae-Jong-Gyo, or Great Dan-Gun Teaching. As a spiritual figure, Dan-Gun is still worshipped today as the first ancestor of the Korean people, and remains in the people's minds the firm spiritual root of the Korean nation.