Cài Tāo 蔡絛 (fl. 1124–1150), zì Yuēzhī 約之, hào Bǎinà jūshì 百衲居士, native of Xīnghuà Xiānyóu 興化仙遊 (modern Fújiàn). Youngest son of the Huīzōng-era councillor Cài Jīng 蔡京. Reached the office of Huīyóugé dàizhì 徽猷閣待制. From Xuānhé 6 (1124), with his father’s eyesight failing, Cài Tāo effectively ran the Three Departments in his father’s stead, prompting impeachment by the censors at the end of Huīzōng’s reign. On the Jìngkāng purge of 1126, exiled to Báizhōu 白州 (modern Guǎngxī, Bóbái); internal evidence in the Tiěwéishān cóngtán (entries dated to Shàoxīng 17 [1147] and 18 [1148]) shows he was still living in exile two decades later.
Author of KR3l0051 Tiěwéishān cóngtán 鐵圍山叢談, the Xīqīng shīhuà 西清詩話 (preserved fragmentarily; Chén Zhènsūn alleged it was ghost-written for Cài Tāo by his kè), and the Běizhēng jìshí 北征紀實 in 2 juàn (recording the 1122 punitive campaign against Liáo Yān, casting blame on Tóng Guàn and his elder brother Cài Yōu while shielding their father).
Despite his political disgrace, Cài Tāo’s Huīzōng-court insider knowledge makes him an indispensable witness for the cultural history of the Zhènghé — Xuānhé era, particularly for the imperial collection (Bógǔtú, Xuānhé Shūpǔ, Huàpǔ) and the Dàshèng music reforms which his father chaired. CBDB id 10838 records no lifedates; fl. dates are inferred from his political career (1124 prominence) and the internal references in his bǐjì (down to 1148).