Emperor Daizong of Tang Li Yu: The Restorer in the Zizhi Tongjian and the Hidden Worry of Regional Warlords

Brief Introduction

Emperor Daizong of Tang (Li Yu, 726–779) was the tenth emperor of the Tang Dynasty, the eldest son of Emperor Suzong, and held the temple name Daizong. His reign (762–779) coincided with the later stages of the An Lushan Rebellion, marking a critical turning point for the Tang Dynasty from chaos to order. Historically referred to as the "Guangde Restoration," this period also sowed the seeds of the hidden trouble of regional warlordism. As a topic for knowledge popularization, understanding Daizong helps in grasping the evolution of the mid-Tang political landscape and the game between centralization and local forces.

Core Knowledge Points

1. Succession and Power Seizure: Li Yu's accession to the throne was fraught with twists. The Zizhi Tongjian records that when Emperor Suzong was critically ill, the eunuch Li Fuguo forced the palace with a forged edict, compelling Li Yu to ascend the throne. Subsequently, Li Yu executed Li Fuguo and reclaimed partial imperial power, demonstrating his forbearance and decisiveness.
2. Rebellion Suppression and Compromise: To end the An Lushan Rebellion as quickly as possible, Daizong adopted a strategy of compromise. He recognized the status of the surrendered generals under Shi Chaoyi as Military Commissioners (Jiedushi), forming the separatist situation known as the "Three Towns of Hebei." While this decision bought temporary peace, it led to a decline in central authority.
3. Finance and Diplomacy: He employed Liu Yan to reform salt policy and canal transport, increasing state revenue through the "Salt Monopoly Law." Diplomatically, facing the Tubo invasion of Chang'an, Daizong fled to Shan Prefecture. He later relied on Uighur troops to recover the two capitals, but this came at a heavy cost.

Connection with the Zizhi Tongjian

In the Zizhi Tongjian, the records of Emperor Daizong's period are concentrated in Volumes 221 to 232. When narrating this period, Sima Guang focused not only on the progress of the wars but also emphasized analyzing the political ecology, providing lessons on governance, chaos, rise, and fall for later generations.
* Warning on Eunuch Power: The book details in depth the process of eunuchs like Yu Chaoren holding military power, revealing the beginning of eunuch interference in politics during the mid-Tang Dynasty. Sima Guang used this to warn later generations that inner court power must not spill over.
* Roots of the Regional Warlord Problem: Through Daizong's handling of figures like Puguhuaian and Tian Chengsi, Sima Guang analyzed why the court chose a policy of "tolerance." He pointed out that although Daizong desired restoration, he was constrained by the weakening national strength and had to exchange compromise for peace. This was the institutional root of the regional warlordism that followed.
* A Model of Monarch-Minister Relationship: The book records Daizong's trust in Guo Ziyi, showcasing a model of harmonious monarch-minister relations in chaotic times. By contrasting this with the arrogance of other generals, it highlights Daizong's political wisdom and approach to employing talent.

Historical Evaluation

Emperor Daizong was an emperor who sought survival amidst adversity. He restored the territory of the Great Tang but left behind the lingering trouble of powerful regional warlords. The Zizhi Tongjian offers an objective evaluation of him, acknowledging his merit in restoring the state while warning later generations of the drawbacks of weakened centralization. For modern readers, studying Daizong is not just about understanding history, but also serves as an important case study for understanding power balance and national governance.