Late Northern–early Southern Sòng cí-writer (1088–1156), zì Shēndào 伸道, hào Yǒugǔ jūshì 友古居士 (“Recluse who Befriends Antiquity”), of Pútián 莆田 (Fújiàn). Grandson of the great calligrapher and statesman Cài Xiāng 蔡襄 (1012–1067). In Xuānhé he served as Vice-Magistrate (tōngpàn) at Péngchéng 彭城 (Xúzhōu) — at the same time and bureau as Xiàng Zǐyīn 向子諲, with whom he maintained an extensive chángchóu exchange that is the primary biographical anchor for his cí. After the southern crossing reached the rank of Zuǒ zhōng dàifū 左中大夫 and held magistracies including Hèzhōu 和州. His sole extant work is the Yǒugǔ cí KR4j0018, in one juǎn, preserved in the late-Míng Máo Jìn 毛晉 cutting and reproduced in WYG; modern editions reconstruct around 175 cí. The Sìkù tíyào places him “slightly below Xiàng Zǐyīn” but his peer in talent and brush-force; the relationship makes him a key witness to the late-1120s–1140s transition between the Northern-Sòng gélǜ tradition and the post-southern-crossing patriot-cí.