In the Romance of the Three Kingdoms, Zhao Yun calls himself "Changshan Zhao Zilong", from which we know that Zhao Yun's birthplace is in Changshan County, which is today's Zhengding, Hebei. At the beginning of the establishment of the Western Han Dynasty, Changshan County was called Hengshan County. Later, in order to avoid the name of Liu Heng, the Emperor of Han, Hengshan County was changed to Changshan County.

Avoidance is unique to ancient China, and it must be avoided when encountering the names of previous emperors or elders. This leads to many interesting phenomena.
First, because the name is changed again and again
The historian Liu Zhiji of the Tang Dynasty, Zi Xuan, wrote the book "Stone". After Emperor Xuanzong of Tang ascended the throne, because "several" and "base" were homophonous, the author of "Stone" could only be called Liu Zixuan and not Liu Zhiji. In the Qing Dynasty, in order to avoid the kangxi emperor Ai Xinjue Luo Xuanye's name, Liu Zixuan was changed to Liu Ziyuan. After the Xinhai Revolution, Liu Ziyuan was changed back to Liu Zhiji.
Second, because of avoidance of resignation
Fan Ye, a historian of the Southern Dynasty and the author of the Book of later Han, was appointed Crown Prince Zhan Shi, and Fan Ye's father was named Fan Tai, and "Tai" and "Tai" were homophonous, and Fan Ye could not take office.
The Northern Wei chancellor Li Yanshi was appointed as the Taibao of Shizhong ( 侍中太保 ), and Li Yanshi 's grandfather was named Li Bao , " Bao " was homophonous with "Bao " , and Li Yanshi resigned from his official position as Taibao of Shizhong ( 侍中太保) .
In the same way, Li He's father was named Li Jinsu, so Li He was reported, resulting in him not being allowed to pass the jinshi.
Third, change the official name because of avoidance
The most famous is that because of the avoidance of Tang Taizong Li Shimin, the "Minbu Shangshu" was changed to "Hubu Shangshu". Later, in order to avoid Emperor Gaozong of Tang's Li Zhi, he changed the term "Zhishu Shi Yushi" to "Yushi Zhongcheng" and the "Zhizhong" of each prefecture to "Sima "Sima ". The "Record of Xiaoshitan" that we learned in middle school was written by Liu Zongyuan when he was the Sima of Yongzhou.
Fourth, change the name of the item because of avoidance
What we call pheasants today was called "pheasant" before the Han Dynasty, and the "chicken" at that time referred specifically to domestic chickens. In order to avoid the name of Liu Bang's wife Lü Yan, "pheasant" was renamed "pheasant".
The fate of the yam is also very bumpy. The yam was originally called "potato", because the Tang Dynasty Emperor was called Li Yu, "蓣" and "豫" homophonous, "potato" was renamed "potato medicine". And because Song Yingzong's name is Zhao Shu, "potato medicine" can only be called yam.