Nan'an City in Romance of the Three Kingdoms: The Strategic Pivot of Zhuge Liang's Northern Expeditions

Brief Introduction

Nan'an, located in present-day Longxi County, Gansu Province, was an important city in the Longyou region of the Wei Kingdom during the Three Kingdoms period. Within the narrative system of Romance of the Three Kingdoms, Nan'an is not merely a geographical name, but a key link in Zhuge Liang's "Seizing Longyou" strategy during his first Northern Expedition. As the frontier of Wei's western defense line, Nan'an was known as one of the "Three Commanderies of Longyou" alongside Tianshui and Anding. It was a significant target for Shu Han, aiming to cut off Wei's connection to Liang Province and expand its living space.

Core Knowledge Points

1. Geographic Strategic Value: Nan'an is located at the throat connecting Guanzhong to Liang Province. Controlling Nan'an allowed the Shu army to threaten Wei's western hinterland while acquiring warhorse resources, thereby compensating for Shu Han's disadvantage in cavalry.
2. Differences between History and Novel: In the official history Records of the Three Kingdoms, the governor of Nan'an once surrendered during the early stage of Zhuge Liang's Northern Expedition but later reverted to Wei due to changes in the battle situation. In Romance of the Three Kingdoms, Luo Guanzhong depicts it as an intense military conquest process, adding dramatic conflict.
3. Changes in Ownership: Nan'an was originally under the jurisdiction of Wei's Yong Province. It was briefly occupied during Shu Han's first Northern Expedition, but due to the defeat at the Battle of Jieting, they were forced to withdraw, and Nan'an returned to Wei control.

Connection to the Book Content

In Chapters 88 to 91 of Romance of the Three Kingdoms, the plot regarding Nan'an City closely revolves around Zhuge Liang's Northern Expedition concept from the "Longzhong Plan."

* Attack Plan: During Zhuge Liang's first expedition out of Qishan, he devised a plan to "first seize the five commanderies of Western Shu," which actually meant first attacking the three commanderies of Longyou. The book explicitly records that Zhuge Liang dispatched Zhao Yun to lead troops against Nan'an.
* Battle Twists: Wei's Inspector of Yong Province, Guo Huai, sent his general Wei Zhang to support Nan'an, blocking Zhao Yun around Lingyang Ridge. Zhao Yun found himself in a dangerous situation but was fortunately rescued by reinforcements sent by Zhuge Liang, including Wei Yan and Gao Xiang, demonstrating internal coordination within the Shu army.
* Gained then Lost: Although the Shu army temporarily seized the three commanderies of Tianshui, Nan'an, and Anding, due to Ma Su's loss of Jieting, Zhuge Liang was forced to retreat entirely. The loss of Nan'an after gaining it became a microcosm of the failure of the first Northern Expedition after near success, highlighting the tragic color of "one incompetent general ruins the whole army."

Conclusion

Although Nan'an City is not the absolute protagonist in Romance of the Three Kingdoms, it is a witness to Zhuge Liang's military wisdom and the rise and fall of Shu Han. It symbolizes Shu Han's effort to turn the tide and also foreshadows the difficulties and dangers of the Northern Expedition. For readers, Nan'an City is not just a coordinate on a map, but an important key to understanding the strategic landscape of the late Three Kingdoms period.