Caodong school
Initially, the number of these schools was fixed at nine. Seon was termed the nine mountain schools" at the time. Eight of these were of the lineage of Mazu Daoyi (馬祖道一) (709-788), as they were established through connection with either him or one of his eminent disciples. The one exception was the Sumi-san school founded by Yieom (利嚴) (869-936), which had developed from the Caodong school (曹洞).