Kim Gyo-gak was a Silla prince, who became interested in Buddhism when visiting Tang China. Upon returning to Silla, he decided to become a monk. In 719, he returned to China to cultivate himself at Mount Jiuhua. He died in 794 in Mount Jiuhua, at the age of 99. The monks there believed that Ksitigarbha was reincarnated in him. Mount Jiuhua thereafter became the sacred site of Ksitigarbha and one of the four sacred mountains of Chinese Buddhism.