The Collapse of Central Authority and the Rise of Regional Warlords

The An Shi Rebellion (755–763) marked one of the most devastating crises in Tang Dynasty history, shattering the empire’s golden age and accelerating the decentralization of military power. By 758, the rebellion had entered its fourth year, and the Tang court’s inability to decisively crush the insurgents led to a dangerous shift—regional military governors (jiedushi) began operating with increasing autonomy. The siege of Yecheng (modern-day Anyang) and the subsequent failures of the Tang forces exposed the weaknesses of centralized command, paving the way for the Fanzhen (military-governed provinces) system that would dominate late Tang politics.

The Siege of Yecheng: A Military and Political Quagmire

In late 758, Shi Siming, a key rebel leader, mobilized his forces from Fanyang and sent his general Li Guiren to seize Fuyang. Meanwhile, the Tang court dispatched nine military governors to besiege Yecheng, where the rebel leader An Qingxu was trapped. However, the lack of a unified command structure proved disastrous. The governors, including the renowned Guo Ziyi, opted for a prolonged siege, even diverting the Zhang River to flood the city. Despite these efforts, infighting and strategic blunders undermined the campaign.

The Tang forces’ disarray was epitomized by the fiasco at Weizhou. The defection of Xiao Hua, a former Tang official turned rebel, offered a chance to turn the tide, but his arrest by rebel forces dashed these hopes. Cui Guangyuan, tasked with retaking Weizhou, failed spectacularly by abandoning defensive tactics for a reckless field battle. His defeat and the subsequent massacre of 30,000 civilians by Shi Siming’s troops deepened local resentment toward the Tang court—a grievance that would fuel future rebellions.

The Mutation of the Pinglu Army: Birth of the First Autonomous Fanzhen

The Pinglu Army’s transformation into a de facto independent warlord force exemplified the broader militarization of Tang frontier units. Initially loyal to the court, Pinglu officers like Liu Kenu (later renamed Liu Zhengchen) and Wang Xuanzhi repeatedly switched allegiances, assassinating rival commanders and carving out personal fiefdoms. After Wang Xuanzhi’s death, the army’s soldiers openly defied central authority by appointing their own leader, Hou Xiyi—a precedent for military self-governance.

Pinglu’s later migration to Shandong and its evolution into the Pinglu-Ziqing节度使 highlighted the soldiers’ growing consciousness as a self-interested corporate body. When Hou Xiyi’s mismanagement provoked a mutiny, the troops expelled him and installed Li Huaixian (later renamed Li Zhengji) as their leader. The court’s rubber-stamp approval of this coup underscored its impotence.

The Battle of Yecheng and Its Aftermath: The Decentralization of Power

The Tang’s catastrophic defeat at Yecheng in March 759—marked by a freak sandstorm that scattered the imperial armies—accelerated the warlordization of regional forces. Routed troops looted civilian settlements, and commanders like Lu Jiong, unable to control their men, committed suicide. The survivors, such as Li Guangbi and Wang Silu, retreated with their forces intact, further consolidating their autonomy.

Meanwhile, Shi Siming exploited the chaos to eliminate An Qingxu and absorb his remnants, declaring himself the “Great Sage Yan King.” His subsequent invasion of Henan forced the Tang to reorganize its defenses, but internal power struggles persisted. Emperor Suzong’s distrust of Guo Ziyi led to the general’s recall, sparking unrest in the Shuofang Army. Only the intervention of subordinate officers like Pugu Huai’en prevented open rebellion.

The Legacy of the An Shi Rebellion: A Fractured Empire

By 760, the Tang Dynasty had irrevocably fractured. The Fanzhen system, born from military necessity, became a permanent feature of late Tang politics. Soldiers now viewed their armies as livelihood providers rather than instruments of the state, while regional governors balanced nominal allegiance to the court with de facto independence. The rebellion’s aftermath also saw the rise of eunuch influence in the military, as emperors sought to counterbalance warlord power.

The An Shi Rebellion thus marked not just a military conflict but a socio-political revolution. It dismantled the centralized Tang state, replacing it with a patchwork of militarized zones whose leaders would shape China’s history for centuries to come. The rebellion’s lessons—about the dangers of unchecked military autonomy and the fragility of imperial unity—resonated far beyond the Tang, influencing later dynasties’ approaches to governance and regional control.