The location was at Mount Xingshi (興勢山), which is situated north of present-day Yang County, Shaanxi, and is now part of the Changqing National Nature Reserve.
Despite facing strong opposition in the Wei court, Cao Shuang believed that the campaign was viable, especially when the Shu commander, Jiang Wan, withdrew his main force from Hanzhong to Fu County (涪縣) in October 243.
Cao Shuang and his protégés concluded that with numerical superiority, their army could easily conquer Hanzhong before Shu reinforcements arrive.
Even if they failed to eliminate Shu, the fall of Hanzhong would be sufficient to increase Cao Shuang's fame and influence in the Wei court.
However, if Shu was on the offensive, it could easily threaten Chang'an by taking this route, and that was the exact suggestion Wei Yan proposed to Zhuge Liang before the first Northern Expedition.
As a result, logistical problems crippled the invasion force, with many if not most of the packing animals of the Wei army dying of thirst before even getting out of the valley.
Cao Shuang was forced to mobilise tens of thousands of draftees as coolies to carry supplies, and many of them met the same fate as the packing animals.
In April 244, Cao Shuang promoted Xiahou Xuan to General Who Subdues the West, and the Inspector of Yong Province, Guo Huai, was appointed as the vanguard commander.
The primary target of the Wei invasion force was Yangping Pass (陽平關; located west of present-day Wuhou Town (武侯鎮), Mian County, Shaanxi).
[10] Wang Ping ordered the General Who Protects the Army, Liu Min, to take up a position in Mount Xingshi (興勢山) and plant an array of flags over a hundred miles long to create the illusion that the Shu defense force was larger than it actually was.
[11] Wang Ping then personally led an army behind Liu Min to prevent possible separate assaults by Wei forces from Huangjin Valley (黃金谷; located east of Mount Xingshi).
[23] For his victory, Fei Yi was awarded the title of "Marquis of Chengxiang" (成鄉侯), and stayed in Hanzhong until his return to the capital Chengdu in September 244.
In contrast, the prestige and popularity of Cao Shuang dropped sharply, which helped lead to his eventual downfall in the power struggle against Sima Yi.