The Collapse of the Yan Dynasty: The Tang’s Decisive Campaign Against An Qingxu and Shi Siming

The Fragmented Remnants of An Qingxu’s Rebellion

By the early months of 758 AD, the once-mighty Yan dynasty established by An Lushan had fractured into isolated pockets of resistance across northern China. Following major Tang victories, key cities including Dezhou (Pingyuan Commandery) and Beizhou (Qinghe Commandery) had surrendered to imperial forces. Even Neng Yuanhao, the formidable defender of Qingzhou (Beihai Commandery), had previously capitulated. This left the desperate An Qingxu controlling just six strategic commanderies in Hebei province – a dwindling empire where loyalty was maintained through increasingly brutal measures.

The Yan ruler’s paranoia reached terrifying heights after his generals Cai Xide and An Taiqing recaptured the surrendered Dezhou and Beizhou in the third month of the Qianyuan era (758 AD). The captured prefects Wang Jian and Yu Wenkuan suffered horrific public executions by lingchi (slow slicing), intended as a warning to potential defectors. An Qingxu implemented draconian policies where entire tribes would be executed for suspected disloyalty among non-Han troops, while Han Chinese faced clan-wide extermination. These terror tactics created an atmosphere of pervasive fear among Yan officers and officials, many of whom saw their families slaughtered for imagined conspiracies.

The Blood Oath at Ye City

In a desperate attempt to solidify wavering loyalties, An Qingxu ordered his remaining officials to participate in a solemn blood oath at the southern outskirts of Ye City (modern Anyang County). This ancient ritual, conducted atop a specially constructed altar, was meant to bind participants through sacred vows against betrayal. The ceremony’s theatrical gravity couldn’t mask the crumbling foundations of An Qingxu’s rule – a regime sustained more by fear than genuine allegiance.

Meanwhile, the Tang court faced its own challenges with the mercurial Shi Siming, who had nominally surrendered but remained deeply untrusted. The brilliant strategist Li Guangbi convinced Emperor Suzong that Shi Siming’s submission was merely tactical, leading to a covert assassination plot involving the turncoat official Wu Chengen. This operation would have profound consequences for the ongoing campaign.

The Tang Counteroffensive Gains Momentum

By the ninth month of 758 AD, Emperor Suzong mobilized an unprecedented force – nine regional military commissioners including the legendary Guo Ziyi and Li Guangbi, amassing 200,000 troops to finally crush An Qingxu. Notably, the emperor deliberately avoided appointing an overall commander, reflecting deep-seated suspicions toward military leaders following An Lushan’s rebellion. This critical decision to place the inexperienced eunuch Yu Chao’en as overseer rather than a unified military leadership would later prove disastrous.

The campaign initially saw spectacular successes. Guo Ziyi’s forces crossed the Yellow River at Xingyuan, capturing Huojia County with 500 prisoners. Coordinated movements by other Tang generals created a pincer movement around the critical Wei Prefecture. At the Battle of Weizhou, Guo Ziyi’s feigned retreat lured An Qingxu’s forces into a deadly ambush where 3,000 hidden archers decimated the Yan army. The Tang forces pressed their advantage, killing 30,000 rebels and capturing An Qingxu’s brother An Qinghe, who was promptly executed.

The Siege of Ye City: A Turning Point

As Tang forces besieged Ye City (Xiangzhou), the strategic situation appeared dire for An Qingxu. The city’s formidable defenses, however, combined with growing disorganization among the nine Tang armies, created a stalemate. Guo Ziyi implemented a brutal blockade, diverting the Zhang River to flood the city. The rising waters forced residents to live on wooden platforms as food supplies dwindled to horrific extremes – rats became currency, selling for 4,000 coins each, while people scraped grain husks from mud walls for sustenance.

The prolonged siege exposed critical flaws in Tang strategy. Without unified command, the nine armies operated at cross-purposes, their initial momentum dissipating into desultory containment. The death of valiant general Li Siye during a failed assault further demoralized Tang forces. This operational paralysis created an opening for the lurking threat of Shi Siming to dramatically alter the campaign’s trajectory.

Shi Siming’s Calculated Intervention

The cunning Shi Siming had been biding his time since his nominal surrender. After crushing the Tang’s assassination plot against him (which resulted in Wu Chengen’s gruesome execution), he openly rebelled again. When the desperate An Qingxu offered to abdicate in exchange for military aid, Shi Siming saw his opportunity. His intervention followed a masterful strategy:

1. Initial victories at Weizhou where he used psychological warfare (fake defector claims) to induce Tang commander Cui Guangyuan to execute his own officer Li Chuyin
2. A dramatic self-proclamation as “Great Sage King of Yan” in early 759 AD, signaling his imperial ambitions
3. Tactical positioning of forces to pressure Tang armies without committing to full engagement

Shi Siming’s approach maximized Tang disorganization while conserving his own strength. His forces harassed Tang supply lines with captured uniforms and insignia, creating paralyzing confusion. When the decisive battle finally came at the Anyang River in the third month of 759 AD, a freak sandstorm triggered a chaotic rout of the massive Tang army, with soldiers abandoning armor and weapons in their panic.

The Fall of An Qingxu and Shi Siming’s Rise

The Tang collapse at Anyang temporarily saved An Qingxu, but merely delayed his inevitable downfall. In a masterstroke of political theater, Shi Siming first lured An Qingxu into a false sense of security with brotherly overtures, then publicly denounced him for patricide (killing An Lushan) during their meeting. The execution of An Qingxu and his key ministers in April 759 AD marked the official end of the An family’s rebellion after three tumultuous years.

Shi Siming’s subsequent consolidation of power was methodical:
– Immediate absorption of An Qingxu’s remaining forces
– Strategic appointments of loyalists like Zhou Zhi as chancellor
– Formal declaration as Yan Emperor with a new “Tianshun” era name
– Establishment of Youzhou (modern Beijing) as his southern capital

This transition, however, merely shifted rather than resolved the conflict. The Tang dynasty now faced an arguably more formidable opponent in the experienced Shi Siming, setting the stage for Li Guangbi’s brilliant defensive campaigns at Heyang and the eventual final suppression of the rebellion.

Military Innovations and Tactical Genius

The conflict produced remarkable examples of military ingenuity on both sides. Li Guangbi’s defense of Heyang showcased psychological warfare at its finest – from the famous “mare strategy” that captured Shi Siming’s cavalry horses by exploiting their attraction to Tang mares, to the anticipatory defense against fire ships using enormous hooked poles. His understanding of human psychology was equally sharp, as demonstrated by the bloodless surrender of Yan generals Li Riyue and Gao Tinghui through calculated displays of trust and honor.

The campaign also highlighted evolving siege technologies, including:
– Sophisticated flood tactics (Tang) vs. elevated living platforms (Yan)
– Mobile “sheep-horse cities” as temporary fortifications
– Tunnel warfare in the final assault on Huaizhou
– Psychological operations using captured soldiers to demoralize enemies

Legacy and Historical Significance

The collapse of An Qingxu’s regime marked a critical phase in the eight-year An Shi Rebellion that devastated Tang China. Several enduring lessons emerged:

1. Leadership Dynamics: The contrast between An Qingxu’s paralyzing paranoia and Shi Siming’s strategic patience demonstrated how personality shaped military outcomes. The Tang’s lack of unified command similarly showed the costs of political distrust overriding operational needs.

2. Military Evolution: The conflict accelerated innovations in combined arms warfare, psychological operations, and siege technologies that would influence East Asian warfare for centuries.

3. Political Consequences: While the Tang eventually prevailed, the rebellion’s suppression came at tremendous cost – weakened central authority, empowered regional governors, and economic devastation that presaged the dynasty’s long decline.

4. Cultural Impact: The prolonged warfare inspired literary works like Du Fu’s “Three Officials” and “Three Departures” poems, capturing the human toll. Archaeological finds like Shi Siming’s jade funeral tablets and tomb artifacts continue to enrich our understanding of this pivotal era.

The An Shi Rebellion’s second phase, culminating in An Qingxu’s downfall and Shi Siming’s rise, remains a textbook study in the interplay of military strategy, political psychology, and the unpredictable role of environmental factors (like the Anyang sandstorm) in shaping history’s course. Its lessons about balancing centralized control with operational flexibility, the dangers of excessive suspicion in leadership, and the importance of logistical planning continue to resonate in military academies worldwide.