Zhuge Liang's Northern Expeditions - First Expedition

First Expedition

At Hanzhong, Zhuge Liang held a war council on the method of realization of the tactical objective of capturing Chang'an. He proposed a wide left hook to seize the upper Wei River valley as a necessity to the capture of the city itself. General Wei Yan, however, objected to the plan and suggested a bold strike through a pass in the Qin Mountains with 10,000 elite troops to take Chang'an by surprise. He was confident that he could hold the city against Cao Wei until the main forces of Zhuge Liang arrived. Wei Yan's plan was rejected by Zhuge as being too ambitious; he preferred a more cautious approach.

In the spring of 228, two small forces were sent through Ji Gorge, one of which was commanded by the veteran general Zhao Yun, as decoys to give the appearance of threatening Mei. The real objective, however, was to seize the Longyou area far west of Chang'an: Tianshui, Anding, Nan'an commanderies and most of all of Mount Qi, the defensive bastion that screened the upper Wei valley.

Cao Rui, the Emperor of Cao Wei, himself moved to Chang'an to oversee the defense. General-in-chief Cao Zhen secured Mei against Zhao Yun whilst a combined cavalry-infantry force of 50,000 under Zhang He were sent west to oppose Zhuge's main army.

Sima Yi put down Meng Da's rebellion, which was co-ordinated with Zhuge Liang. Meng Da was taken by surprise as he had not expected Sima Yi to attack without seeking court approval.

At Jieting, the strategic outpost crucial to future Shu supplies, Wei general Zhang He found a weakness of Shu's arrangement–the larger part of the advance guard of Shu was entrenched on a nearby mountain top. Thus, Zhang He forfeited access to water supplies, and Shu vanguard was easily defeated. The minor part of the vanguard stationed on the mountain road broke through Wei ranks and the remnants fled south, only escaping total annihilation due to Zhang He's fear of ambush. Meanwhile Zhao Yun's small intrusion against Mei met with stiff resistance and Zhuge Liang ordered a general withdrawal to Hanzhong at the prospect of an outflanking motion by Wei army. Following his defeat, Zhuge Liang had the vanguard leader, Ma Su, executed for the tactical blunder at Jieting, and a memorial published to Liu Shan, in which he chastised himself for the failure and requested demotion from Chancellor (宰相) to General of the Right (右将军), but Zhuge Liang would wield the same power even after demotion.