Yixi Year 6: Liu Yu's Northern Expedition and the Turning Point of the Jin Dynasty's Fate

Brief Introduction

Yixi Year 6, corresponding to 410 AD, was the era name used by Emperor An of Eastern Jin, Sima Dezong. This year coincided with a critical juncture in Chinese history, marking the end of the Sixteen Kingdoms period and the eve of the Southern and Northern Dynasties. The Later Qin regime in the north was crumbling, while the Eastern Jin court in the south still existed but was dominated by powerful ministers. Yixi Year 6 became a significant turning point for the Eastern Jin Dynasty, marking its transition from decline to eventual fall, due to the major military actions of the northern expedition general Liu Yu intertwined with internal rebellions. It also laid the foundation for the subsequent establishment of the Liu Song regime.

Core Knowledge Points

* Time Positioning: Yixi Year 6 corresponds to 410 AD, belonging to the late Eastern Jin period.
* Key Figures: Liu Yu (Emperor Wu of Song), who was already the actual ruler of Eastern Jin at this time; Yao Hong (Emperor of Later Qin); Lu Xun (Rebel General of the Jin Dynasty).
* Major Events:
1. Northern Expedition against Later Qin: Liu Yu led an army to breach the Later Qin capital Chang'an, captured Yao Hong, destroyed the Later Qin regime, and recovered large swathes of lost territory in the north.
2. Lu Xun Rebellion: During Liu Yu's northern expedition, Lu Xun, who came from a pirate background, took the opportunity to rise up, advancing directly toward the Eastern Jin capital Jiankang (present-day Nanjing), threatening the survival of the court.
3. Strategic Choice: Between Chang'an and Jiankang, Liu Yu ultimately chose to abandon the newly recovered northern achievements and lead his main forces south to quell the rebellion.
* Historical Impact: Although this northern expedition did not completely unify the north, it greatly enhanced Liu Yu's personal prestige and military power, accelerated the decline of Eastern Jin imperial authority, and marked the beginning of the process of "Song replacing Jin".

Connection with "Zizhi Tongjian" Content

In the Zizhi Tongjian, compiled by Sima Guang, the records of Yixi Year 6 are mainly concentrated in the Jin Records section. Sima Guang, in a chronological form, meticulously recorded the military details of Liu Yu's northern expedition and the urgent situation of Lu Xun's rebellion.

The book particularly highlights the dilemma faced by Liu Yu: whether to remain in Chang'an to consolidate northern achievements or return to Jiankang to protect the foundation? Through narrative, the Zizhi Tongjian implies that while Liu Yu's choice to return saved the regime's foundation, it also led to the loss of Chang'an shortly thereafter, causing the great cause of northern unification to fail at the last hurdle. Sima Guang used this event to demonstrate the strategic game of "consolidation" versus "advance" in chaotic times. This passage is not only a record of military history but also a profound analysis of the process of power transfer, providing important historical data for later generations to understand the succession of regimes during the Southern and Northern Dynasties. Consequently, Yixi Year 6 became one of the core chapters in the Zizhi Tongjian depicting the situation on the eve of the Eastern Jin's fall.