Cài Kān 蔡戡 (b. 1141, zì Dìngfū 定夫, hào Dìngzhāi 定齋), great-great-grandson of the Northern-Sòng calligrapher and statesman Cài Xiāng 蔡襄 (1012–1067) of Xiānyóu 仙遊 in Xīnghuàjūn 興化軍 (modern Fújiàn). His grandfather Cài Shēn 蔡紳 settled the family at Wǔjìnxiàn 武進縣 in Chángzhōu 常州 (modern Jiāngsū) during Shàoxīng. Jìnshì of Qiándào bǐngxū (1166), passing in jiǎkē. Held office to Bǎomógé zhí xuéshì, with substantial regional administrative service: Jīngxī yùnpàn, Guǎngdōng yùnpàn, Húběi xiàn, Jīngzhào yǐn, Húnán and Huáixī zǒnglǐng, and Guǎngxī jīnglüè. Sòngshǐ did not give him a biography — the Sìkù editors regarded this as an omission and reconstructed his career from his collection KR4d0258. CBDB id 3860 (death year not recorded; alive at least until close to 1230, when his collection was first cut). Author of KR4d0258 Dìngzhāi jí.