Was There Another Plan Behind Han Xin’s Back-to-the-River Formation?
Contents
Introduction
I love the drama and romance of Chinese history.
One period I find especially fascinating runs from the end of the Qin dynasty through the Chu–Han Contention. It’s full of remarkable figures, led by Xiang Yu, the Hegemon-King of Western Chu, and Liu Bang, Emperor Gaozu, founder of the Han dynasty that would endure for some 400 years across its Western and Eastern periods.
The stories about this era in the Shiji are undeniably dramatic and entertaining, but they also contain many things that seem distinctly unnatural or invite questions.
By the time Sima Qian wrote the Shiji, the Chu–Han Contention was already roughly a century in the past. Detailed records were probably missing in places, and colorful anecdotes had likely become hard to distinguish from historical fact.
One episode that puzzled me was the Battle of Jingxing, the origin of the expression “fighting with one’s back to the river.” Even allowing for Han Xin’s reputation as an unmatched military genius, doesn’t everything work out a little too conveniently?
I’ve arrived at an interpretation that makes sense to me, so I thought I’d write it down.
The Familiar Account of the Battle of Jingxing
For anyone unfamiliar with it, here’s an outline of the battle.
It was 204 BCE. China was divided between Xiang Yu of Chu and Liu Bang of Han, who were fighting for supremacy in the Chu–Han Contention.
Han’s celebrated general Han Xin advanced into Zhao to subdue it as an enemy of Han. But he had just sent troops to reinforce Liu Bang’s short-handed main army, leaving him with a total force of around 30,000.
Chen Yu, the chancellor who held power in Zhao, met him with a large army said to number 200,000.
Han Xin drew up his troops with a river behind them, contrary to conventional military wisdom. Seeing this, the Zhao soldiers mocked him for not understanding even the basics of warfare and attacked with their full force.
Although Zhao had an overwhelming numerical advantage, Han Xin’s men fought desperately with no route of escape and could not be broken. Unable to finish them off, the Zhao army tried to retreat to its stronghold, only to see something astonishing: Han banners were flying everywhere. Han Xin had detached 2,000 men to attack from behind and seize Zhao’s base.
With their base taken, the Zhao troops fell into confusion and routed. Chen Yu was captured and executed.
Han Xin’s complete victory against overwhelming numbers became one of the legendary battles of this extraordinary general.
My Questions
Winning such an overwhelming victory with an unconventional back-to-the-river formation must have become legendary even at the time. That’s how the expression survived to the present day.
But I have two questions about the Shiji’s account of the battle.
Why Did Chen Yu Leave His Rear So Poorly Defended?
Chen Yu supposedly commanded 200,000 men. Yet while he attacked Han Xin’s river-backed position, a detachment of just 2,000 men captured his base.
Even if he wanted to commit everything to a decisive battle, would he really leave his base so exposed?
The base should also have had some defensive works. Even if it was lightly guarded, it feels odd that 2,000 men could seize it almost instantly.
Why Did Han Xin Choose Such a Risky Plan?
The river-backed formation is often presented as the reason for victory. But as the outline shows, the decisive factor was the successful surprise attack on Zhao’s base. In the Shiji’s account, that was Han Xin’s only route to victory. If the detachment had been repelled, his army would have been trapped in enemy territory, with the river behind it and overwhelming forces in front, and would presumably have been annihilated.
Would a renowned general as well versed in warfare as Han Xin stake everything on a single surprise attack, with total destruction as the price of failure?
My Interpretation: The Real Purpose of the Formation
My theory is that Han Xin’s real advantage at Jingxing, though it wasn’t recorded, was that he had persuaded an influential figure in Zhao to defect. Let me explain why I think this.
It Gives the Formation a Different Purpose
Consider the following scenario, based on that hypothesis.
Before setting out, Han Xin had successfully persuaded a reasonably powerful figure in Zhao to change sides.
To make the most of that defection by capturing Zhao’s base, he devised the river-backed formation. Perhaps its main purpose was to create an apparent opportunity and draw Chen Yu out to the front line.
Why Draw Chen Yu Out?
It seems natural to imagine Han Xin thinking along these lines:
- To make the defection and seizure of the base succeed, he needed to keep Chen Yu and his main army firmly occupied at the front.
- If Zhao stayed behind its defenses and aimed for a prolonged siege, the risk of exposing the betrayal would rise.
Chen Yu and his main army did indeed march out to attack Han Xin’s river-backed position. But rather than leaving the base virtually empty as the Shiji’s description suggests, he would presumably have left a sizeable garrison.
However, some of those defenders had already been won over by Han.
Battle and Betrayal
I think Han Xin may have been almost certain that a defection inside Zhao’s base would lead to its fall. All his river-backed troops needed to do was act as a decoy and buy enough time, and victory would be assured.
Until then, he could rely on the morale generated by having no retreat and on the river restricting the enemy’s attack to one direction. Chen Yu had a large army, but the river prevented encirclement and made it harder to exploit that numerical advantage.
In the rear, just as Han Xin intended, his detachment’s surprise attack would signal part of Zhao’s garrison to defect, and the base would fall easily. What happened afterward would follow the Shiji’s account.
This Hypothesis Doesn’t Contradict the Account or the Circumstances
Han Xin’s Indirect Approach
The Shiji does describe Han Xin gathering intelligence from inside the Zhao army. Thinking that he was also working to win people over seems quite natural.
It even says he knew about the exchange between Chen Yu and the Zhao general Li Zuoche. Wouldn’t it be natural to suppose he had a highly placed informant able to attend Zhao’s senior councils and pass along that information?
The Weakness of Chen Yu’s Regime and the Role of Zhang Er
One person inseparable from Chen Yu’s story is Zhang Er, Han Xin’s deputy commander in this battle.
Chen Yu and Zhang Er had originally been close friends. But amid the chaos and wars at the end of Qin, Zhang Er came to distrust Chen Yu, their relationship collapsed, and they became enemies. Jingxing was also the final chapter of their struggle to the death.
Chen Yu had gained control of Zhao by defeating Zhang Er, who had been recognized as a leading figure there, through military force. Chen Yu wasn’t a member of Zhao’s royal family either; he had risen to power amid the collapse of Qin.
Given that background, Chen Yu’s hold on power was probably far from secure. There may have been supporters of Zhang Er still in Zhao, or opportunities to win people over through his connections. Wouldn’t it be natural for Han Xin to recognize this weakness and use Zhang Er to encourage defections?
Why Is There No Surviving Record Supporting This Interpretation?
By their nature, political maneuvers and secret collusion may have been unlikely to leave clear records. Furthermore, Han Xin and three branches of his family were exterminated in the early Han period. That may also have prevented detailed accounts of his campaigns and methods from surviving.
I think it’s quite possible that by the time Sima Qian compiled the Shiji, detailed inside accounts had been lost, leaving only dramatic events and entertaining anecdotes as legend.
Summary
Under this hypothesis, Han Xin had already secured a route to victory by arranging defections beforehand. The back-to-the-river formation was merely the finishing tactic. That would embody the idea in Sun Tzu that victorious troops secure victory first and then seek battle, while defeated troops fight first and only then seek victory.
Rather than the familiar story of taking a daring, high-risk gamble and winning, this interpretation suggests a victory characteristic of a commander deeply versed in warfare. To me, that feels more like Han Xin.
Afterword
Whatever actually happened, as a Han Xin fan, I’m uncomfortable when “back to the river” is used simply to mean trying desperately hard.
Even in the surviving Shiji account, he gathers intelligence, prepares carefully, and uses the formation only to get through the decisive moment once he has sound reasons to expect victory.