Origins
A Branch of the Xun Surname
The Zhonghang surname derives from the Xun surname; tradition holds that the Yellow Emperor had twenty-five sons, who were divided into twelve surnames, one of which was Xun.
Reference: 中行氏,中行姓起源,中行氏,中行姓介绍 - 百家姓 - 族谱录
Surname Formation in the Spring and Autumn Period
During the Spring and Autumn period, Xun Ying and Xun Yan of Jin served respectively as commander of the Central Army and commander of the Upper Army. To distinguish them, Xun Ying took the name of his father's fief, Zhi, as his clan name, while Xun Yan was called the Zhonghang clan because he served as a Zhonghang general.