The Precarious Inheritance of Emperor Dezong

When Emperor Dezong (Li Shi) ascended the throne in 779 CE, the Tang Dynasty stood at a crossroads. His father, Emperor Daizong, had spent his reign stabilizing the empire after the catastrophic An Lushan Rebellion (755–763 CE), but the dynasty remained weakened by rebellious military governors (jiedushi) and aggressive neighbors like the Uighur Khaganate and Tibet. Dezong inherited a realm where central authority was nominal at best—a reality that would define his tumultuous reign.

The international landscape further complicated matters. The Uighurs, once crucial allies against An Lushan, had grown fat on Tang subsidies and plunder. Their leader, Tengri Bögü Khan, had abandoned nomadic traditions for a decadent, Sinicized court life—complete with palaces and concubines—funded by extorting the Tang. This corruption sowed internal dissent, foreshadowing the Uighurs’ decline. Meanwhile, Tibet, though militarily formidable, faced unsustainable losses against Tang border defenses.

The Uighur Crisis and a Narrow Escape

Dezong’s reign nearly began with disaster. When his father died in 779 CE, Tengri Bögü Khan—egged on by Sogdian advisors—planned a full-scale invasion, seeing the mourning period as opportune. The Uighur chancellor Tun Bagha Tarkhan, however, recognized the folly:

“The Tang is a mighty empire that has never wronged us. Remember our last raid—we seized thousands of sheep and horses, yet our men returned on foot, starving. If we invade and fail, how will we retreat?”

When Tengri Bögü refused to listen, Tun Bagha exploited Uighur war-weariness to overthrow him, executing the khan and 2,000 Sogdians. The new ruler promptly submitted to Dezong, marking the Uighurs’ irreversible decline. Over the next 60 years, ten khans would fall in a cycle of coups mirroring the chaos in Tang’s northeastern military districts.

This unexpected submission likely emboldened Dezong’s confrontational stance—a miscalculation that would soon backfire.

The Powder Keg of Provincial Power

The real threat lay within. Military governors like Li Baochen of Chengde Circuit had operated as de facto kings, passing titles to heirs despite imperial bans. When Li Baochen died in 781 CE, his son Li Weiyue concealed the death for 20 days while bribing envoys to secure succession. Dezong, determined to reassert control, refused—ignoring warnings that rejection meant war.

Li Weiyue’s advisor Shao Zhen pleaded:
“The Son of Heaven seeks to unify the realm. If you rebel, every defeated battle will turn your generals against you. Remember how Tian Chengsi nearly lost everything before begging for mercy!”

But Li Weiyue, paranoid and inept, poisoned his uncle (a seasoned strategist) and aligned with rebel governors like Tian Yue of Weibo. The stage was set for the Four Provinces’ Rebellion—a conflict that would expose Dezong’s flawed leadership.

A Court of Fools and Fiends

Dezong’s domestic policies proved equally disastrous. After executing reformist minister Liu Yan, chancellor Yang Yan blamed the emperor to appease critics—a fatal error. Dezong, enraged, promoted Yang’s nemesis Lu Qi to orchestrate his downfall.

Lu Qi, a blue-faced grotesque with a vindictive streak, was uniquely unqualified. Even the dying general Guo Ziyi had warned:
“Lu Qi is ugly outside but uglier within. If he gains power, my family will perish.”

True to form, Lu Qi had Yang Yan exiled and strangled, then consolidated power by purging rivals. His rise symbolized Dezong’s deteriorating judgment—a flaw that would soon cost the emperor dearly.

The Unraveling

By 781 CE, Dezong faced simultaneous crises:
– Military Revolts: The Chengde refusal ignited rebellions across Hebei and Shandong.
– Diplomatic Blunders: Alienating the Uighurs and Tibet created volatile borders.
– Court Instability: Lu Qi’s tyranny eroded governance.

When Tibetan envoys later saw Dezong weeping during a siege (783 CE), they regretted their earlier submission. The emperor’s humiliation underscored a bitter truth: his rigidity had squandered Daizong’s hard-won stability.

Legacy of a Fragmented Empire

Dezong’s reign (779–805 CE) became a cautionary tale. His refusal to compromise with provincial leaders triggered decades of warfare, while his trust in sycophants like Lu Qi weakened the bureaucracy. Though the Tang survived, the empire never fully recovered its central authority—a decline culminating in the 907 CE collapse.

The lesson was clear: in a world of nomadic threats and entrenched warlords, even a “righteous” emperor could doom his realm through pride and poor counsel. Dezong’s near-failure reminds us that survival often hinges not on ideals, but on pragmatic alliances—and knowing which battles to avoid.