Late-Sòng / Yuán-period 宋元 classicist, native of Póyáng 鄱陽 county in Ráozhōu 饒州 (modern Jiāngxī). Zì Jìhēng 季亨; hào Shēnshān 深山. Lifedates not securely recorded; CBDB id 21917 has no firm dates. Catalog meta gives floruit “13th century” but his work draws on materials by 陳櫟 (1252–1334) and 吳澄 (1249–1331, who wrote a preface to Shū zhuàn jí lù zuǎn zhù), so a defensible floruit window is c. 1290–1330.
Dǒng Dǐng’s intellectual lineage runs through Huáng Gàn 黃榦 (1152–1221), Zhū Xī’s son-in-law and chosen successor: his clan-elder-brother Dǒng Mèngchéng 董夢程 had studied under Huáng Gàn directly, and Dǒng Dǐng learned from Dǒng Mèngchéng. He therefore claims the status of Zhū Xī’s zài chuán 再傳 (“twice-transmitted disciple,” i.e. at two generational removes), as he says in his autograph preface to the Shū zhuàn jí lù zuǎn zhù. He is likely also indirectly affiliated with the BěiShān / Wùzhōu network (via Huáng Gàn → Hé Jī → Wáng Bǎi → Jīn Lǚxiáng → Xǔ Qiān: see 金履祥 and 許謙).
His one surviving major work is the Shū zhuàn jí lù zuǎn zhù 書傳輯錄纂註 (KR1b0029), a 6-juǎn sub-commentary on Cài Shěn’s Shū jízhuàn (KR1b0017) that takes the Jízhuàn as base, appends Zhū Xī’s Yǔlù and miscellaneous writings (the jí lù 輯錄 = “Compiled Records”), and collects supportive readings from later commentators (the zuǎn zhù 纂註 = “Compiled Annotations”). In YuánMíng Shū literature he is regularly cited as “Mr Dǒng of Póyáng” or “Shēnshān Dǒngshì” 深山董氏. Methodologically he is one of the most independent of the Yánȳòu-era examination orthodoxy commentators: while framing his work as a ZhūXī orthodox sub-commentary on Cài Shěn, in practice he tacitly diverges from Cài on a number of important readings — see the Sìkù’s analysis at KR1b0029.