The Powder Keg: Origins of the An Lushan Rebellion

The An Lushan Rebellion (755–763 CE) was not merely a revolt—it was the seismic event that fractured the Tang Dynasty’s golden age. To understand its roots, we must examine the systemic failures that allowed ambition to exploit structural weaknesses.

### The Collapse of the Equal-Field System

At the heart of the crisis lay the disintegration of the Equal-Field System (均田制), a land redistribution policy inherited from the Northern Wei Dynasty. Designed to allocate state-owned land to peasants in exchange for taxes and military service, its success relied on two fragile conditions: abundant arable land and controlled population growth. By the mid-8th century, neither held true.

– Demographic Pressure: Under Tang prosperity, China’s population surged, outpacing land availability.
– “Floating Households” (浮逃户): Peasants, unable to sustain tax burdens, abandoned registered lands, eroding the tax base.
– Military Consequences: The Equal-Field System’s collapse crippled the Fubing System (府兵制), a militia-style force tied to land grants. By 737 CE, the Tang resorted to mercenary recruitment (募兵制), a fateful pivot.

### The Rise of the Jiedushi and a Reversed Power Balance

The Tang’s new professional army, the “Long Campaign Braves” (长征健儿), was concentrated under regional military governors (jiedushi). This reversed the traditional “strong core, weak periphery” (内重外轻) defense strategy, creating a volatile “strong periphery, weak core” (外重内轻) dynamic.

– An Lushan’s Power Grab: As governor of Pinglu, Fanyang, and Hedong, An commanded 180,000 troops—nearly one-third of Tang forces.
– Strategic Resources: He secured warhorses from state pastures (陇右群牧使) and built the Xiongwu Fortress as a rebel stronghold.
– Ethnic Dimensions: Though often framed as “ethnic conflict” (An was of Sogdian-Turkic descent), his coalition included Han Chinese elites like Gao Shang and Yan Zhuang, revealing a multi-ethnic power struggle.

The Rebellion Unleashed: A Dynasty in Flames

### The Spark and the Firestorm

In December 755, An Lushan declared himself emperor of the Great Yan Dynasty, marching south from Fanyang (modern Beijing). His forces—hardened by wars against the Khitan—sacked Luoyang and Chang’an, forcing Emperor Xuanzong to flee.

– The Fall of Chang’an (756 CE): The Tang capital’s capture marked the dynasty’s nadir.
– Mawei Slope Incident: En route to Sichuan, imperial guards mutinied, killing Yang Guozhong and demanding Yang Guifei’s execution—a symbolic purge of “the root of treason.”

### Xuanzong’s Fatal Miscalculations

The emperor’s divide-and-rule tactics—pitting factions like the northeastern warlords against northwestern generals—backfired catastrophically.

– Overreliance on Mercenaries: Professional soldiers owed loyalty to paymasters, not the throne.
– Neglect of Central Defense: The capital’s garrisons were hollowed out while border armies swelled.

Cultural and Societal Upheavals

### The Great Southward Migration

As war ravaged the north, mass migrations to the south reshaped China’s demographic and economic landscape.

– Cultural Diffusion: Refugees like poet Du Fu carried northern traditions to the Yangtze basin.
– Economic Rebalancing: Southern agriculture and trade flourished, laying groundwork for the later Song Dynasty’s economic pivot.

### Ethnic Repercussions and the “Uighur Problem”

The Tang’s reliance on Uighur mercenaries to quell the rebellion entrenched their influence, exacerbating tensions:

– Post-War Extortion: Uighur troops looted Luoyang in 762, demanding exorbitant “rewards.”
– Legacy of Distrust: Anti-Hu sentiment surged, though the rebellion’s causes were institutional, not ethnic.

The Tang’s Fractured Legacy and Beyond

### The Shattered Empire

The rebellion’s aftermath saw:
– Territorial Losses: Tibet seized the Hexi Corridor; the Tang never regained Central Asia.
– Rise of Regionalism: Semi-autonomous jiedushi eroded central authority, foreshadowing the Five Dynasties chaos.

### Lessons for the Song Dynasty

The Song’s founding ethos—”Emphasize Civil, Restrain Military” (扬文抑武)—was a direct response to Tang militarization:

– Dismantling Warlordism: Zhao Kuangyin’s “Cup of Wine” reforms centralized power.
– The Paradox of Peace: Song stability came at the cost of military weakness—a tradeoff haunting Yue Fei’s doomed career.

Conclusion: Why An Lushan Still Matters

The rebellion was more than a dynastic crisis—it redefined China’s political philosophy, ethnic relations, and economic geography. Its echoes resonate in modern debates about centralization vs. regional autonomy and the perils of military privatization.

As Tang poet Du Mu lamented: “The empire rises and falls like the moon’s phases—but the heartbreak of war endures.” The An Lushan Rebellion remains a stark reminder: prosperity, unchecked by vigilance, carries the seeds of its own destruction.