Zhuge Liang
Ziwu Campaign

In August 230, Cao Zhen led an army from Chang'an to attack Shu via the Ziwu Valley (子午谷). At the same time, another Wei army led by Sima Yi, acting on Cao Rui's order, advanced towards Shu from Jing Province by sailing along the Han River. The rendezvous point for Cao Zhen and Sima Yi's armies was at Nanzheng County (南鄭縣; in present-day Hanzhong, Shaanxi). Other Wei armies also prepared to attack Shu from the Xie Valley (斜谷) or Wuwei Commandery.

When he heard of Wei recent movements, Zhuge Liang urged Li Yan to lead 20,000 troops to Hanzhong Commandery to defend against the Wei invasion which he reluctantly accepted after much persuasion. As Xiahou Ba led the vanguard of this expedition through the 330 km Ziwu Trail (子午道), he was identified by the local residents who reported his presence to the Shu forces. Xiahou Ba barely managed to retreat after reinforcements from the main army arrived.

Zhuge Liang also allowed Wei Yan to lead troops behind the ennemy lines towards Yangxi (陽谿; southwest of present-day Wushan County, Gansu) to encourage the Qiang people to join Shu Han against Wei. Wei Yan greatly defeated Wei forces led by Guo Huai and Fei Yao. Following those events, the conflict became a prolonged stalemate with few skirmishes. After more than a month of slow progress and by fear of significant losses and waste of resources, more and more Wei officials sent memorials to end the campaign. The situation wasn't helped by the difficult topography and constant heavy rainy weather lasting more than 30 days. Cao Rui decided to abort the campaign and recalled the officers by October 230.
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