The Strategic Chessboard of Ancient China

In the spring of 205 BCE, the political landscape of China resembled a massive game of weiqi, with warlords maneuvering across the Central Plains like stones on the board. Liu Bang, now styling himself as the King of Han, emerged from his Hanzhong stronghold with ambitions that stretched far beyond the mountain passes that had confined him. The once-united anti-Qin coalition had fractured into competing kingdoms, with Xiang Yu’s Western Chu dominating as the nominal hegemon from his capital at Pengcheng.

The campaign began with remarkable success as Liu Bang’s forces swept through Henei commandery. His proclamation offering “ten-thousand-household marquisates” to any regional commander who defected with substantial forces proved devastatingly effective. Local officials, weary of constant warfare and impressed by Liu Bang’s reputation for clemency, surrendered their cities in rapid succession. Within weeks, the Han army ballooned from its core of 30,000 veterans to a staggering 400,000 troops – though many were inexperienced conscripts or opportunistic defectors.

The Capture of Yin Kingdom

The first major test came at the Yin capital of Zhao Ge, where King Sima Ang had barricaded himself, desperately awaiting reinforcements from Xiang Yu that would never arrive. Han Xin, Liu Bang’s brilliant but unconventional general, employed a classic feigned retreat strategy. He ordered his vanguard commander Guan Ying to deploy visibly weakened troops, luring Sima Ang’s general Zhao Ben into an ill-advised sortie. When Guan Ying’s forces suddenly counterattacked amid the disorganized Yin troops scrambling for abandoned Han equipment, the city fell within hours.

This victory demonstrated Han Xin’s tactical genius and marked a turning point in the campaign. The capture of Sima Ang provided Liu Bang not just with another surrendered king to add to his growing collection of vassal rulers, but control over the strategic region that opened the path directly toward Pengcheng. As Liu Bang established his headquarters at Xiuwu, the psychological impact reverberated across the warring states – the Han momentum appeared unstoppable.

The Gathering Storm at Pengcheng

Pengcheng (modern Xuzhou) stood as the glittering prize – Xiang Yu’s capital and the symbolic heart of Western Chu power. The city’s fall would represent more than a military victory; it would shatter the aura of invincibility surrounding the Chu hegemon. Liu Bang’s confidence grew as reports confirmed Xiang Yu remained mired in suppressing the Qi rebellion far to the northeast.

The strategic calculus seemed perfect: while Xiang Yu’s main forces were distracted, Liu Bang could strike at the weakly defended Chu heartland. His advisors presented diverging views. Chen Ping, the recent Chu defector, passionately advocated immediate action, producing detailed maps of Pengcheng’s defenses. In contrast, the cautious Zhang Liang and even the normally aggressive Han Xin urged restraint, warning that engaging the legendary Xiang Yu directly remained extremely hazardous.

Liu Bang, intoxicated by his rapid successes and the prospect of dealing a decisive blow, chose audacity over caution. He consolidated his forces at Luoyang, where a dramatic political theater unfolded that would shape the campaign’s narrative.

The Masterstroke of Political Theater

An encounter with an 82-year-old village elder named Master Dong proved pivotal. The sage advised Liu Bang to transform his campaign from a territorial grab into a moral crusade by publicly mourning the murdered Yi Emperor – the puppet ruler installed during the anti-Qin rebellion whom Xiang Yu had secretly assassinated.

Liu Bang immediately recognized the propaganda value. He staged three days of elaborate public mourning outside Luoyang, with all officials baring their right arms in mourning attire while the army wore white headbands. Chen Ping drafted a fiery proclamation condemning Xiang Yu’s regicide and calling on all righteous men to join the punitive expedition.

This brilliant piece of political theater accomplished several objectives simultaneously: it provided moral justification for Liu Bang’s aggression, appealed to former loyalists of the Yi Emperor, and most importantly, attracted additional allies. Soon, letters arrived from King Tian Guang of Qi and the guerrilla leader Peng Yue pledging support. Even the hesitant Zhao and Dai kingdoms under Chen Yu agreed to join – though only after Liu Bang (through a macabre deception involving a lookalike’s severed head) pretended to execute his old ally Zhang Er.

The Illusion of Victory

When Liu Bang’s colossal army – now swollen to 560,000 men from multiple kingdoms – finally descended on Pengcheng in late April, the outcome seemed foreordained. The city’s meager garrison under Yu Ziqi collapsed within hours against the human tide. Chu officials including the strategist Fan Zeng barely escaped with their lives, fleeing northward in disarray.

The intoxicating ease of victory proved Liu Bang’s undoing. Rather than consolidating his position and preparing for Xiang Yu’s inevitable counterattack, the Han forces indulged in an orgy of looting and celebration. Chu palace treasures were distributed among the troops while Liu Bang himself enjoyed the former Chu royal concubines. The strict discipline that had characterized earlier Han campaigns evaporated in the heady atmosphere of conquest.

Critical strategic errors compounded the complacency. Despite warnings from his more cautious advisors, Liu Bang concentrated most forces within Pengcheng rather than maintaining strong defensive positions in the surrounding terrain. Only a token force of 100,000 was stationed at Xiaoxian to guard the supply lines – a decision that would soon prove disastrous.

The Dragon’s Wrath: Xiang Yu’s Lightning Strike

While Liu Bang reveled, Xiang Yu reacted with terrifying decisiveness. Upon learning of Pengcheng’s fall, he handpicked 30,000 elite cavalry and embarked on one of history’s most audacious forced marches. Avoiding direct routes blocked by Han forces, Xiang Yu looped east through Lu territory before suddenly turning south toward Huling – a maneuver that completely bypassed Han defenses.

The speed and secrecy of this movement became legendary. By maintaining strict noise discipline and concealing banners, the Chu cavalry moved like ghosts through the countryside. Local farmers mistook them for routine patrols, while Han scouts failed to recognize the danger until it was too late.

Xiang Yu’s first strike annihilated the Han garrison at Xiaoxian in a dawn attack, severing Liu Bang’s supply lines and escape route west. Before news could reach Pengcheng, the Chu cavalry had already repositioned west of the city – precisely where the Han leadership least expected attack.

The Disaster at Sui River

The ensuing battle became less a military engagement than a massacre. As the disorganized Han forces stumbled out of Pengcheng to face this unexpected threat, Xiang Yu’s cavalry struck with hurricane force. The numerical advantage of Liu Bang’s army proved meaningless against the shock of heavy cavalry attacking from an unexpected direction.

Panic spread instantly through the Han ranks. What began as orderly retreats of individual units quickly degenerated into a chaotic rout as hundreds of thousands of men fled northeast toward the supposed safety of the Gu and Si rivers. The geography that should have protected Pengcheng now became a death trap – with Chu cavalry herding the terrified Han soldiers into the waterways where tens of thousands drowned.

The Sui River became the scene of the worst carnage. Hemmed in between the pursuing Chu forces and the impassable river, entire Han divisions were pushed into the waters until, as Sima Qian recorded, “the Sui River ceased to flow from the corpses.” King Sima Ang of Yin died fighting bravely in the rearguard, while Wei Bao of Wei suffered grievous wounds.

Liu Bang’s Narrow Escape

Liu Bang’s personal survival bordered on miraculous. Trapped near the Sui River with Chu forces closing in, only an opportune sandstorm (later mythologized as divine intervention) allowed his small retinue to escape westward. Even then, the pursuit nearly proved fatal – at one point Liu Bang repeatedly threw his own children from his chariot to lighten the load, only for his driver Xiahou Ying to keep retrieving them.

The aftermath revealed the scale of the catastrophe. Of the 560,000 coalition troops that had taken Pengcheng, perhaps 100,000 eventually regrouped. The rest lay dead, captured, or scattered across the countryside. All the surrendered kings except Wei Bao abandoned the Han cause. The strategic initiative had abruptly shifted back to Xiang Yu, while Liu Bang’s reputation lay in tatters.

Yet in this darkest hour, the seeds of eventual Han victory were already germinating. The Pengcheng campaign, despite its disastrous conclusion, revealed several enduring truths: the power of political propaganda (as demonstrated by the Yi Emperor mourning), the importance of logistical planning (fatally neglected after the capture of Pengcheng), and above all – as Liu Bang would later grudgingly admit – that defeating Xiang Yu would require patience and indirect strategies rather than head-on confrontation.

The lessons learned from this catastrophic defeat would shape Liu Bang’s approach for the remainder of the Chu-Han contention, ultimately leading to the trap at Gaixia four years later where the roles would be perfectly reversed, with Xiang Yu surrounded and Liu Bang holding the strategic advantage. But in the summer of 205 BCE, such an outcome seemed unimaginable to all except perhaps the most far-sighted strategists like Zhang Liang and Han Xin.