The Sajasan sect was located at Heungnyeongsa-ji Temple Site in Yeongwol, Gangwon-do. Now the temple is known as Beopheungsa Temple, and it’s also a Jeokmyeol-bogung site (a shrine containing sari relics of the Historical Buddha, Seokgamoni-bul, as established by the monk Jajang-yulsa), as well. The temple was first founded by the monk Doyun (798-868 A.D.). Doyun’s posthumous name is Cheolgam.
For the longest time, Doyun resided at Ssangbongsa Temple in Hwasun, Jeollanam-do. For this reason, Doyun is also known as Ssangbong. Doyun’s family name was Bak, and his mother was from the Go clan. Before Doyun was born, his mother had a dream. In this dream, the sleeping chamber she was sleeping in was filled with a supernatural light. She then became pregnant after having this dream and gave birth to Doyun some sixteen months later. At eighteen, Doyun became a monk. And in 825 A.D., he traveled to Tang China (618–690, 705–907 A.D.) and received the dharma from Chan Master Nanquan Puyan (749-835 A.D.). Master Puyuan said of Doyun when he was returning to Silla, “The dharma seal of our sect goes to Silla.”
Doyun would return to Silla in 847 A.D. First he resided at Mt. Pungaksan. Later, he would return to Ssangbongsa Temple, where he passed away in 868 A.D. at the age of seventy-one. A five coloured light radiated from his mouth and miraculous light illuminated the entire sky. It was his disciple, Jinghyo Jeoljung (826-900 A.D.) that would found the Sajasan sect during the reign of King Heongang of Silla (r. 875-886 A.D.). And it was from here that Doyun’s teachings would spread.