The Historical Mirror of Zhonghang Xue: From Surrendering to the Xiongnu to Shaping the Han-Xiongnu Dynamic

Brief Introduction

Zhonghang Xue was a highly controversial and profoundly influential historical figure during the Western Han Dynasty. Originally a eunuch in the Han imperial court (serving as a Zhonglang in the Zhonglangshu agency), he was forced to go into exile and serve as an envoy to the Xiongnu due to certain incidents (reportedly a false accusation of plotting rebellion). Ultimately, he chose to surrender and remained in the northern steppe. In Xiongnu territory, Zhonghang Xue not only became an advisor to the Chanyu (the Xiongnu leader) but also leveraged his in-depth understanding of Han military systems to provide the Xiongnu with critical advice on weakening the Han’s military advantages. This profoundly altered the trajectory of the Han-Xiongnu wars in the mid-to-late Western Han period.

Core Knowledge Points

1. The Strategy of “Depriving China of Cattle and Horses”
The core strategy Zhonghang Xue proposed to the Chanyu was not merely a plan for military raid, but rather a combination of intelligence and psychological warfare. He pointed out that Han soldiers long wore heavy armor and padded clothing for combat to adapt to the cold climate of the Central Plains. Zhonghang advised the Xiongnu to launch surprise attacks during winter (or summer) and cut off the links between the Central Plains and the border commanderies, preventing Han cavalry from assembling quickly. More importantly, he exploited the Han army’s characteristic of “valuing armor while neglecting heavy cavalry,” inducing the Han forces to engage under unfavorable conditions. This caused the Han army to lose its advantages due to cumbersome equipment and overly extended supply lines.

2. Disrupting the Han-Xiongnu Economic Trade
Beyond military strategies, Zhonghang Xue also severed the Han dynasty’s material dependence on the Xiongnu. Prior to this, the Xiongnu relied heavily on silk, grain, and metal tools obtained from the Han. By persuading the Chanyu, Zhonghang successfully restricted the Han-Xiongnu trade. He attempted to exchange Xiongnu-produced furs and hides for Han silk. Although the practical effect was limited, this move significantly weakened the Han’s ability to contain the Xiongnu through economic means.

3. The Long-term Value of Covert Intelligence
As a eunuch in the Han palace, Zhonghang Xue was well-versed in the Han court’s decision-making processes, the weaknesses of border generals, and the logic of military deployments. He converted this first-hand intelligence into tactical advice, enabling the Xiongnu to move from passive defense to anticipating Han military actions. In the environment of information asymmetry at that time, this provided a devastating advantage.

Connection to Records in the Book of Han

The biography and deeds of Zhonghang Xue are primarily recorded in the Book of Han: Western Regions and the Book of Han: Xiongnu.

In the Book of Han: Xiongnu, it is detailed how Zhonghang Xue “secretly taught the Chanyu how to control China” during his time with the Xiongnu. The text specifically notes that Zhonghang once persuaded the Chanyu: “China gives away cattle and horses; let China give away cattle and horses…” (Here, “give away” in classical Chinese often refers to “gift” or “remain/abandon.” Combined with the context, this actually refers to Zhonghang’s advice for the Chanyu to exploit the weakness of Han cattle and horses, or deliberately abandon some horses to exhaust the Han cavalry’s advantage. Some scholars interpret this as cutting off the supply of horses to make the Han army deficient in mounts). This record reveals how Zhonghang Xue used the information gap to allow the Xiongnu to take the military initiative.

At the same time, the Book of Han implicitly reflects on the strategic dilemma caused by Zhonghang Xue when evaluating the wars during Emperor Wu of Han’s reign. Although the Han possessed strong national power, the Xiongnu, relying on the targeted tactics provided by Zhonghang Xue, forced the Han army into exhausting campaigns with limited results. This, to a certain extent, delayed the Han’s complete resolution of the northern border threat, becoming a key case of “internal leakage” in Western Han military history.

Through the figure of Zhonghang Xue, we can see the complex interweaving of ancient intelligence warfare and individual fate within national maneuvering.