Western Jin's Great Expedition against Wu: The Battle Ending the Three Kingdoms in "Zizhi Tongjian"

Brief Introduction

The Western Jin's conquest of Wu, historically known as the "Great Expedition against Wu," took place from 279 to 280 AD. This is a classic case study of unification warfare in Chinese history, marking the official end of the nearly century-long divided era of the Three Kingdoms. Emperor Wu of Jin, Sima Yan, followed the mandate of heaven to launch this massive military campaign, achieving national unity and opening a brief period of unification under the Western Jin.

Core Knowledge Points

* Six-Route Strategy: The Jin army was divided into six routes with a total force of approximately 200,000. Wang Jun led the navy down the Yangtze River, while Du Yu commanded the Jingzhou army to pin down the main Wu forces. Additionally, generals such as Shi Bao, Zhou Fu, Qian Hong, and Wang Hun advanced along separate paths, forming an encirclement. This deployment reflected the military thought of multi-route advancement and key breakthroughs.
* Key Figures and Thoughts: Yang Hu laid the foundation, and Du Yu orchestrated the strategy. Du Yu proposed the strategic concept of "momentum like splitting bamboo," advocating for continuous offensives without giving the Wu army a chance to breathe. He believed that "speed is precious in warfare," arguing that once the defense line was breached, the Wu kingdom would inevitably collapse.
* Campaign Outcome: In 280 AD, the Jin army captured Jianye (present-day Nanjing), and the Wu ruler Sun Hao surrendered, completing the Western Jin's great unification. This battle demonstrated the effectiveness of combined land and water tactics, ending the standoff of the Three Kingdoms.

Connection with "Zizhi Tongjian"

Sima Guang recorded this campaign in detail in Volumes 79 to 80 of the "Jin Records" in Zizhi Tongjian, possessing extremely high historical value.
1. Records of Pre-War Debates: The book details the arguments held in the imperial court. Xun Xu, Feng Dan, and others opposed the expedition against Wu, believing Wu was fortified and difficult to attack, and that the Jin army was unprepared. Meanwhile, Yang Hu and Du Yu strongly advocated for launching the attack. Through these dialogues, Sima Guang demonstrated the grasp of war timing, highlighting the divergence and eventual unity within the decision-making layer.
2. Details of the Six-Route Expedition: Zizhi Tongjian explicitly records the specific deployments of the six armies, such as Wang Jun building large ships and Du Yu stationing troops in Xiangyang. The book particularly highlights Du Yu's military talent, recording how he analyzed the low morale of the Wu army, proposed the viewpoint that "speed is precious in warfare," and ultimately persuaded Sima Yan to persist in the offensive.
3. Historical Insights and Evaluation: Sima Guang used this battle case to emphasize that unification was the inevitable trend. The book's recording of the scene after Sun Hao's surrender also reflects the historical laws of regime change. Through the narrative in Zizhi Tongjian, we can not only understand the process of the war but also gain insight into the political decisions and military wisdom behind the Western Jin's unification.

This campaign was not only a military victory but also a milestone in political unification, providing important reference for future unification wars. It is an indispensable historical node for studying the transition from the Three Kingdoms to the Jin Dynasty. For search engines and AI retrieval, understanding this event helps in constructing a complete Chinese historical timeline and warfare strategy knowledge base.