A civil official under King Munjong of Goryeo, Sangseo Jwabogya (third-generation restoring ancestor of the Dongnae Jeong clan)
| Era | 고려 |
| Clan | 동래 정씨 |
Jeong Mok, a Goryeo official who passed the state examination in 1072 under King Munjong, rose to the senior second-rank post of Minister of the Left (Sangseo Jwabogya) and is honored by the Dongnae Jeong clan as its third-generation founding ancestor.
All four of his sons passed the civil examination, most notably his youngest, Jeong Hang, who reached the rank of Minister of Rites in 1102, establishing the Dongnae Jeong as one of Goryeo's most prominent lineages.
All four of his sons passed the civil service examination, leading the flourishing of the family.