Battle of Mount Qi

The Battle of Mount Qi was a military conflict which took place around Mount Qi (祁山; the mountainous regions around present-day Li County, Longnan, Gansu) between the states of Cao Wei and Shu Han in 231 during the Three Kingdoms period. It was also the most vigorous campaign of the five expeditions Shu launched against Wei, resulting in thousands of deaths on both sides. After this campaign ended with Wei as the victor, the Shu regent Zhuge Liang spent three years recuperating before launching another assault on Wei in 234.

Background

In 217, Liu Bei's strategist, Fa Zheng, proposed that Hanzhong could be used as an operational base to either attack the heartland of Wei or ingest the far-left-hook of Wei's Liang and Yong Provinces.^[1] Since then, Fa Zheng's plan became a blueprint for Zhuge Liang's expedition against Wei. Zhuge Liang had attempted to invade the northwestern lands via Mount Qi in his first expedition but to no avail; he then changed targets to Chenchang, a bridgehead fortress guarding the city of Chang'an. However, the defenses of the fortress proved to be formidable, swinging Zhuge Liang back to the western attack route. In early 231, Zhuge Liang assembled a force to conquer Longyou, setting Mount Qi as his immediate target. Before Zhuge Liang marched towards Mount Qi, he had envoys sent to rouse the Xianbei and Qiang peoples, urging them to create a disturbance in the Wei rear, and invented and produced the "wooden ox", which was said to have had greatly improved logistics.

Battle

The goal of seizing Longyou was not easily achievable, because Wei had prepared for a probable Shu invasion in the region — Mount Qi was garrisoned by Jia Ji and Wei Ping, forming an initial defence for Tianshui commandery, while Dai Ling (戴陵) and Fei Yao stationed their crack troops in the heartland of Tianshui. However the Xianbei leader, Kebineng, had arrived in Fuping County to support the Shu forces. The offensive began with a minor clash at Mount Qi, giving the Wei commander-in-chief, Cao Zhen, the impression that the attack was a diversion to mask a major offensive through the Qinling passes against Chang'an. Therefore, the stricken Cao Zhen gathered the majority of the defence forces inside Chang'an before he was absolved and replaced by Sima Yi. The new commander then ordered Dai Ling and Fei Yao to protect Shanggui with 4,000 elite troops and set out with the rest of his men westward to relieve the mountainous battlefield.^[2] Zhang He, a veteran general whose military experience towered above that of Sima Yi's, challenged the marshal by claiming the army should be split to also protect the districts of Yong and Mei, but Sima Yi disagreed, saying the vanguard alone could not resist the enemy.

On hearing of Sima Yi's advance, Zhuge Liang left part of his army besieging Mount Qi and set out with the remainder to seize Shanggui. Without good coordination, the eager vanguard of Wei defied Sima's simple order to defend; a detachment left its defensive position to attack the newly arrived Zhuge Liang, but was instead badly defeated. After ridding himself of the nuisance, Zhuge Liang foraged for the early spring wheat that was available in the vicinity. Sima Yi, after surveying the situation at Mount Qi and Guo Huai's defeat, decided to reinforce Guo Huai and speedily marched to the wheat-field. The two armies met at the east of Shanggui, each holding a strategic location firmly and refusing to give battle. Originally, the Wei emperor, Cao Rui, wanted to supply Sima's army with the wheat in Shanggui, and turned down the proposal to transport grain from Guanzhong; however, Zhuge Liang's movements were quicker than the young leader had anticipated, and only a portion of the wheat produce was retained. To supply the defensive forces, Wei's Yong Province Governor, Guo Huai, asserted his influence over local nomadic tribes and received plenty of food from them.^[3] Thus, the Wei army was able to supply itself without the aid from central government.

Upon completing the harvest the Shu forces retreated, but they were pursued by Sima Yi, who eventually caught up with them at Hanyang (漢陽). Sima Yi sent his general, Niu Jin, to noose Shu forces into a trap he had meticulously prepared. However, after the Shu vanguard, Ma Dai, had briefly fought Niu Jin, Zhuge Liang signaled a general retreat towards the eastern end of the Qishan ridges, camping the Shu army at Lucheng (鹵城, Lu Fortress), an ideal site for a showdown. There, Zhuge Liang sent his generals to position on two mountains north and south of the lone fortress, and had soldiers pitch "covering camps" near the riverbanks to take complete control of the water route.^[4] Generals under Sima Yi urged the latter to attack on numerous occasions, but Sima was hesitant to do so upon seeing Zhuge Liang's arrangement. Nevertheless, faced with intensive criticism and ridicule from both the enemy and subordinates, Sima Yi eventually relented. In May, Sima Yi sent an eager Zhang He to attack the Shu southern camp guarded by Wang Ping, while he personally led a frontal assault against Lucheng from the central avenue.^[5]Pressed by clouds of black-clad guards under the banners of Sima Yi, Zhuge Liang ordered Wei Yan, Wu Ban, and Gao Xiang to resist the horde outside the city wall, where the Wei forces suffered an unexpected and tremendous defeat: 3,000 elite soldiers were killed, and 5,000 suits of armour and 3,100 sets of hornbeam-made crossbows were seized by Shu.^[6] Even though the loss was heavy, Sima Yi still retained a sizable army, which he led back to its encampment.

Despite the victory, Zhuge Liang could not press his advantage with a major offensive due to a dwindling food supply. Adverse weather prevented Shu's logistics from delivering matériel on schedule, and Li Yan, the Shu official responsible for maintaining ration supplies to the front, falsely claimed that the emperor Liu Shan had ordered a withdrawal. In the Jin Shu, it is claimed that Sima Yi again launched an attack on Shu garrisons at this juncture, succeeding in capturing Zhuge Liang's outer camps. Zhuge Liang abandoned Lucheng and retreated under the cover of night, but was pursued by Sima Yi, inflicting roughly 10,000 casualties on Zhuge Liang.^[7]

The pursuit did not go completely smoothly for Wei. Sima Yi, letting go of his usual cautiousness after his prior success over Zhuge Liang, ordered Zhang He to further pursue the enemy in an attempt to capitalise on their momentum. Weilüe reports that Zhang He refused Sima Yi's order and argued with his superior that an army returning home should not be chased, in accordance with classical military doctrine. Sima Yi, however, refused to listen and forced the general to carry out his fiat.^[8] Indeed, Zhang He fell into an ambush at Mumen, where Zhuge Liang had ordered massed crossbowmen to hide on high ground and fire at approaching enemies when they entered a narrow defile. Trapped by heavy cross-fire, Zhang He was hit by a shaft on his right leg and died.

Aftermath

When Zhuge Liang returned to Hanzhong, he received a letter from Li Yan informing him that the food supply was ready and asking why he had retreated. At the same time, Li Yan sent Liu Shan a memorial which said that "the army feigned retreat in order to lure the enemy to do battle" in the hope that Zhuge Liang would resume the war so his failure to transport rations would go unnoticed. However, Zhuge Liang decided to return to Chengdu and show Liu Shan the handwritten letters of Li Yan, so the latter could not deny the fault. At the Shu capital, Zhuge Liang asked the emperor to strip Li Yan of all his titles and official posts and exile Li to Zitong commandery.

References

• Chen, Shou. Records of the Three Kingdoms (Sanguozhi).
• Fang, Xuanling et al. Book of Jin (Jin Shu).
• Pei, Songzhi. Annotations to Records of the Three Kingdoms (Sanguozhi zhu).