Northern-Sòng Tiāntái 天台 master of the shānjiā 山家 lineage; sobriquet Cǎotáng 草堂 (“Thatched-Hall”; also referenced as Cǎotáng Chǔyuán 草堂處元), official title Sēngzhèng 僧正 (“Sangha-Inspector”). DILA Authority A001138. Born 1030; died c. 1119–1120, aged 90.
Major work: the Móhē zhǐguān yìlì suíshì 摩訶止觀義例隨釋 (KR6d0141, X56n0923, 6 juan) — a Northern-Sòng running subcommentary on Zhànrán’s Zhǐguān yìlì (KR6d0132, T1913), parallel to Cóngyì’s Zuǎnyào (KR6d0139).
Chǔyuán’s productive period (c. 1060–1119) overlaps substantially with Cóngyì’s (1042–1091) and Yǒuyán’s (1021–1101), placing him in the second-and-third generation of the post-Zhīlǐ shānjiā tradition.
Sources: Shìshì yínián lù 釋氏疑年錄ʔ; DILA A001138.