Records of the Three Kingdoms
Dong Yun, courtesy name Xiuzhao, was from Zhijiang in Nanjun. His father Dong He was known under both Liu Zhang and Liu Bei for severity and fairness. Dong Yun and Fei Yi were gentlemen of the heir’s household. In the memorial before the northern campaign Zhuge Liang entrusted the palace to Guo Youzhi, Fei Yi, and Dong Yun, and said they could manage it.
As palace attendant and acting prefect of the masters of writing, Dong Yun refused Liu Shan when he wanted to take women from among the people into the harem, citing ritual and law. The eunuch Huang Hao feared him and did not dare to run wild. Dong Yun died of illness in 246. Chen Shou’s joint biography of father and son says Dong Yun straightened his lord and the last emperor stood in awe of him. Only after his death did Huang Hao’s place rise.
Romance of the Three Kingdoms
In the novel Dong Yun is the man in the palace who holds Huang Hao down. While he lives, Liu Shan’s follies are stopped. When he dies, Huang Hao begins to meddle, and Jiang Wei is hampered from outside.
The book gives Dong Yun no battlefield. His scenes are all in the palaces of Chengdu.
Reference: Wikipedia · Dong Yun