Later Zhou's Northern Expedition against the Khitan: The Historical Turning Point of Emperor Shizong of Zhou Taking the Guannan Territory in the Sixth Year of Xiande

Brief Introduction

In the sixth year of Xiande (959 AD), after basically unifying the southern regions, Emperor Shizong of Later Zhou, Chai Rong, decided to launch a northern expedition against the Khitan (Liao Dynasty). The aim was to recover the Sixteen Prefectures of Yan and Yun, which had been ceded by Shi Jingtang. Although the expedition was brief, the Zhou army advanced like a sweeping bamboo, successfully recovering the Guannan Three Passes (Yijin Pass, Waqiao Pass, and Yukou Pass). However, due to Emperor Shizong suddenly falling ill with dysentery, he was forced to withdraw his troops. This unfinished northern expedition not only altered the geopolitical landscape of the Five Dynasties and Ten Kingdoms period but also laid the groundwork for the national defense strategy of the later Northern Song Dynasty, making it one of the most important military actions at the end of the Five Dynasties and Ten Kingdoms.

Core Knowledge Points

* Time and Person: The sixth year of Xiande (959 AD), led by Emperor Shizong of Later Zhou, Chai Rong, hailed as the "First Enlightened Monarch of the Five Dynasties." His military prowess reached its peak during this campaign.
* Strategic Goal: To recover the Sixteen Prefectures of Yan and Yun, eliminate northern border threats, open up the natural barrier between agricultural and nomadic regions, and restore the former territories of the Han and Tang dynasties.
* Battle Process: The Zhou army employed a light cavalry rapid advance tactic, bypassing the main Khitan force to strike directly at southern Youzhou. They consecutively conquered the three passes. Khitan defenders fled at the sight of the Zhou troops, and morale within Youzhou city wavered, with some Khitan nobles even willing to surrender the city.
* Historical Regret: While the war was at its peak, the Emperor was too ill to continue commanding and, fearing instability in the rear, ordered a retreat. The Khitan seized the opportunity to repair the passes, and the Later Zhou lost the prime opportunity to recover Yan-Yun.
* Profound Impact: This northern expedition established the Later Zhou's advantage in the north. However, due to the Emperor's early death, the gains could not be consolidated. It became the biggest strategic burden for Zhao Kuangyin of the Northern Song and his successors, influencing Song border defense policies for a century.

Connection with the Content of "Zizhi Tongjian"

In the Later Zhou records section of the Zizhi Tongjian (Comprehensive Mirror in Aid of Governance), Sima Guang records this campaign in detail, placing it at the climax and turning point of Later Zhou history, possessing extremely high historical value.

1. Contextual Thread: The book previously detailed the process of the Emperor's southern campaign against Southern Tang, military preparation, and reform of the imperial guard. The northern expedition was a natural extension of the "South first, North later" strategy. Sima Guang highlights the Emperor's military talent and grand ambitions by contrasting the northern and southern campaigns.
2. Style and Evaluation: When recording the Emperor's death and the retreat, Sima Guang's brushstrokes reveal deep regret. He cites advice from generals at the time, pointing out that Youzhou could have been captured if the Emperor had not died. This "historian's sigh" reinforces the impact of historical contingency (the Emperor's death) on inevitable trends (unifying the north), reflecting Sima Guang's thoughts on the relationship between circumstances and heroes.
3. Connecting Past and Future: This passage is a key node in the Zizhi Tongjian's transition from the chaos of the Five Dynasties to the unification of the Song Dynasty. Through the failure of the northern expedition, the book explains why the Northern Song still faced diplomatic dilemmas such as the "Chanyuan Alliance" after its establishment, providing a profound historical background for readers to understand the Song Dynasty's policy of emphasizing civil affairs over military matters.

In summary, the northern expedition of the sixth year of Xiande was not only a military action but also a watershed in historical destiny. In the Zizhi Tongjian, it marks the end of the Five Dynasties' hegemony and the beginning of the Song Dynasty's predicaments.