Dong Zhongshu
Dong Jin was born in 724, during the reign of Emperor Xuanzong. His family was from Hezhong Municipality (河中, in modern Yuncheng, Shanxi) and claimed ancestry from the Han Dynasty scholar Dong Zhongshu. Dong Jin's great-grandfather Dong Renwan (董仁琬) served as a prefectural education official, and his father Dong Boliang (董伯良) served as a county secretary. Dong Jin passed the imperial examinations, although it is not clear when that occurred.