A Strategic Nexus in War: Unveiling the Military Significance of "Liuhexian" in the Xu Zizhi Tongjian

Brief Introduction

In the map of ancient Chinese military geography, "Liuhexian" (today's Liuhe District, Nanjing, Jiangsu Province) has long been regarded as a core node of the Jiang-Huai barrier. While references to "Cui Quan defeating the Jin troops" are largely found in folk legends or local chronicles rather than official histories, it is undeniably true that Liuhexian served as a frontline stronghold on the border between the Song and Jin dynasties. This article combines the Xu Zizhi Tongjian with relevant historical materials to analyze the strategic value of Liuhexian in the war against the Jin and the historical logic behind it.

Core Knowledge Points

1. Geographic Strategy: The Gateway to Jiang-Huai

Located north of Yangzhou and east of Nanjing, Liuhexian commands the north bank of the Yangtze River. For Jin forces advancing south to capture Nanjing, Liuhexian was an unavoidable passage; if they sought to move east along the Huai and Si corridors, they would face the diversionary pressure of its garrison forces. In the Song-Jin War, this area represented the "flank" where the Southern Song's defenses were weakest and the "vanguard" where they were most critical.

2. Historical Correction: "Cui Quan" and the Actual Generals

It is important to note that the main text of the Xu Zizhi Tongjian contains no definitive record of "Cui Quan defeating the Jin army." This claim likely originates from later local legends or fictionalized narratives (possibly confusing the surname "Cui" or the toponym "Quan"). Notable historical figures who resisted the Jin in the Liuhexian area include Liu Qi (who fought in the prelude to the Battle of Caishi) and other Southern Song generals who engaged in multiple skirmishes here. Readers should rationally distinguish between official historical records and folk legends, avoiding the conflation of literary narratives with historical facts.

3. The Song-Jin Stalemate: A Contested Frontline

From the Jingkang Incident in 1127 onward, Liuhexian was repeatedly caught in the crossfire of war. Due to its lack of natural defensive advantages yet its elevated position, it became an ideal maneuvering ground for Jin cavalry, while also serving as a critical point for Southern Song infantry to defend using fortifications. Every loss of Liuhexian often meant the opening of the gates to Nanjing; conversely, every recapture signified the stabilization of the Jiang-Huai defensive line.

Connection to the Content of the Xu Zizhi Tongjian

Although the Xu Zizhi Tongjian was compiled by Qing dynasty historians covering the Yuan period, it follows the structure established by Sima Guang’s Zizhi Tongjian and records major events from the Song-Yuan transition in detail. Despite its main timeline being later than the peak of the Song-Jin War, its editorial philosophy of "learning from the past to understand the present" provides significant reference value for analyzing precedents from earlier eras.

1. Continuity of Strategic Thought: In discussing the Yuan conquest of the Song, the book frequently reviews the gains and losses of the Jiang-Huai defensive line, indirectly corroborating the crucial role of northern-bank strongholds like Liuhexian within the system of "using the river as a defense and the Huai River as a barrier."
2. Verification of Military Geography: By comparing records of surrounding campaigns (such as those at Xiangyang and Yangzhou), one can infer Liuhexian's function as a logistical supply line and a point for cavalry intercepts. Even if "Cui Quan" is not a historical figure, the strategic necessity of "defeating the Jin" was real, reflecting the persistent guerrilla defense tactics employed by the Southern Song in the Liuhexian region.
3. Historical Perspective: The Xu Zizhi Tongjian emphasizes that "war is a domain of deception." The repeated struggles over Liuhexian exemplify this military doctrine—priority is not given to holding a single location, but to maneuvering the enemy and wearing down their strength.

Conclusion

Liuhexian is more than just a line on a map; it is a witness to the blood and tears of the Song-Jin War. Distinguishing the truth from the "Cui Quan" legend helps us approach history with greater rigor. Through the macro perspective of the Xu Zizhi Tongjian, we can better appreciate the profound significance of the Jiang-Huai defense line in the context of ethnic integration and dynastic change, thereby transcending the limitations of a single battle to grasp the strategic脉络 (context/trajectory) within the long river of history.