Zhuge Liang's Northern Expeditions

Zhuge Liang's Northern Expeditions were a series of five military campaigns launched by the state of Shu Han against the rival state of Cao Wei from 228 to 234 during the Three Kingdoms period. All five expeditions were led by Shu's chancellor-regent Zhuge Liang. Although they proved unsuccessful and indecisive, the expeditions have become some of the most well-known conflicts of the Three Kingdoms period. In popular history, they overlap with the "six campaigns from Mount Qi", which is inaccurate, since Zhuge Liang only launched his campaigns from Mount Qi twice.

Background
In 227, China was divided into three competing regimes - Cao Wei, Shu Han and Eastern Wu - each with the purpose of reunifying the empire of the fallen Han Dynasty. In the state of Shu, the strategic thinking behind the Northern Expeditions can be traced back as early as 207, when the 27-year-old Zhuge Liang outlined his Longzhong Plan to his lord Liu Bei. In it, he explained in very general terms the need to gain a viable geographical base, and then went on to detail a two-pronged strike north for mastery of the north. One advance would be from Yi Province in the west (covering the Sichuan Basin), north through the Qin Mountains, debouching into the Wei River valley and achieving a strategic position at the great metropolis Chang'an from which to dominate the great bend of the Yellow River. The second advance would be from Jing Province (covering present-day Hubei and Hunan) north toward the political center of Luoyang.

After Liu Bei established himself in Yi Province in 215, the essential prerequisites of the plan had been completed. The geopolitical arrangement envisaged by Zhuge Liang proved, however, to be a militarily unstable one. The alliance with the state of Wu in the east broke down over the issue of the occupation of Jing Province. By 223, the province had been lost and Liu Bei, as well as some of his top generals, were dead. Even after Zhuge Liang re-established friendly relations with Wu, his original plan had been markedly altered since only the left prong could be executed.

In Zhuge Liang's much quoted memorial Chu Shi Biao of 227, he explained to Liu Bei's son and successor Liu Shan in highly ideological terms the reasoning for his departure from the capital Chengdu: "We should lead the three armies to secure the Central Plain in the north. Contributing my utmost, we shall exterminate the wicked, restore the house of Han and return to the old capital. Such is this subject's duty in repaying the Former Emperor and affirming allegiance to Your Majesty."

Geography
Zhuge Liang's plan called for a march north from Hanzhong, the main population center in northern Yi Province. In the third century, the region of Hanzhong was a sparsely populated area surrounded by wild virgin forest. Its importance lay in its strategic placement in a long and fertile plain along the Han River, between two massive mountain ranges, the Qin in the north and the Micang in the south. It was the major administrative center of the mountainous frontier district between the rich Red Basin (Sichuan Plain) in the south and the Wei River valley in the north. The area also afforded access to the dry northwest, and the Gansu panhandle.

Geographically, the rugged barrier of the Qin Mountains provided the greatest obstacle to Chang'an. The mountain range consists of a series of parallel ridges, all running slightly south of east, separated by a maze of ramifying valleys whose canyon walls often rise sheer above the valley streams. As a result of local dislocations from earthquakes, the topographical features are extremely complicated. Access from the south was limited to a few mountain routes called the gallery roads. These crossed major passes and were remarkable for their engineering skill and ingenuity. The oldest of these was to the northwest of Hanzhong, and which crossed the San Pass. The Lianyun "Linked Cloud" Road was constructed there to take carriage traffic during the Qin Dynasty in the third century BCE. Following the Jialing Valley, the route emerges in the north where the Wei River widens considerably, near the city of Chencang. Another important route was the Baoye route, which transverses the Yegu Pass and ends south of Mei. A few more minor and difficult routes lay to the east, notably the Ziwu, which leads directly to the south of Chang'an.

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.

Second expedition
Not long after the end of the first expedition, Eastern Wu inflicted a defeat on Cao Wei at the Battle of Shiting, on the Hefei battlegrounds. Fearing a breakthrough in the Huai River valley, the Wei court decided to reinforce the east by transferring troops from the west. Sensing an opportunity, Zhuge Liang struck in December 228 through Qinling with the aim of capturing Chencang (陳倉), communication thoroughfare of the Wei River.

The walled city was held by Hao Zhao with an estimated 1000 or so soldiers who was warned by Cao Zhen after Zhuge Liang's first campaign to make defensive preparations.

Although hugely outnumbered by the 20,000 to 100,000 Shu troops, Hao Zhao refused requests to surrender. Soon Zhuge Liang brought to bear an array of siege equipment, including scaling ladders, battering rams and archery towers. Nevertheless, Chencang could not be broken and the Wei soldiers provided stubborn resistance with various incendiary devices.

After three weeks, Zhang He arrived with relief troops and food supplies. Zhuge Liang, himself short of grain, ordered a retreat to Hanzhong once more. One of Zhang He's subordinates, Wang Shuang, decided to pursue through the Qin Mountains and was killed by an ambush arranged by Zhuge Liang. This incident, with the victim as one of the champions personally accredited by the Wei emperor, was a shock reminder of the skills of Zhuge Liang as a master of ambuscades.

Third expedition
The spring of 229 saw Zhuge Liang make his third expedition. Setting the immediate goal as the capture of the commanderies of Wudu and Yinping, Zhuge Liang sent Chen Shi to storm the enemy territory before he ventured out. The area Chen Shi was asked to take seated on the western foothills of the Qin Mountains, and could potentially be used as a launch-pad for a further strike toward Tianshui Commandery.

The defending general, Guo Huai, had readied his troops to attack Chen Shui, but drew back as he received intelligence that Zhuge Liang was marching toward Jiawei, a northern county of Wudu Commandery. Although Guo Huai retreated, he secured a defense line to prevent any hostile advance to Tianshui. The Shu regent, in the mean time, was arriving Jianwei, where he would halt his army. After surveying the situation, Zhuge Liang chose to station his army at the relatively remote county, in anticipation of probable Wei reinforcement, which never came to rescue the two commanderies.

The victory, however, did not reap significant strategic benefits for Shu despite the regent's personal political gain; the livestock and tribesmen had already been transported out from the area by Cao Wei, and to station there would be a drain on manpower and rations. Zhuge Liang retreated back to Hanzhong, but in response to the acquisition of two commanderies, the Shu emperor Liu Shan issued an imperial edict and had Zhuge Liang reinstated as Chancellor.

Beginning in the winter of 229 and into the spring of 230, Hanzhong was again involved in new military developments; on knowledge of a Wei offensive, Zhuge Liang initiated extensive preparations, including two defensive barriers on the Hanzhong plain, running 200 kilometers with nearly 100,000 troops. The Wei court had decided to alter its defensive strategy and launched a three-pronged attack with the objective of seizing Hanzhong led by Sima Yi, Cao Zhen and Zhang He.

The Wei offensive began in the fall of 230 with over 400,000 troops; in response Wei Yan and Wu Yi (吳懿) were sent north with a mixed cavalry-infantry force behind enemy lines to incite dissension amongst the various non-Han Chinese ethnic groups within the domain of Wei, while at the same time sell the famous Chengdu silk brocades in return for horses and weapons. Aiding Shu was the fact that Wei attack ran into problems from the beginning: heavy rain continued for more than thirty days and made narrow valleys impassable, while Zhang He in the west had to deal with the threat from rear. After nearly one and a half month of little progress, Wei terminated the disastrous campaign. Zhuge Liang made a daring march northwest in an attempt to relieve Wei Yan, who had been intercepted by Guo Huai on his return; but before Zhuge Liang's reinforcement reached its destination, Wei Yan had already managed to defeat Guo Huai. Thus Shu force was able to make a pround return to Hanzhong.

In many Chinese historical writings and novels, these two battles are classified as separate expeditions although the latter was actually a defensive maneuver and Zhuge Liang never left Shu.

Fourth expedition
Zhuge Liang's fourth Northern Expedition was launched in early 231. Envoys were sent out to rouse the Xianbei and Qiang people, urging them to create a disturbance within Wei's domain. In early summer Cao Zhen took ill and was replaced by Sima Yi, who at once ordered Dai Ling and Fei Yao to protect Shanggui with 4,000 troops, and set out with the main army at Chang'an to relieve Mount Qi. In response to Sima Yi's advance, Zhuge Liang left part of his army besieging Mount Qi and rushed to Shanggui before his nemesis could arrive.

Without a coordinated strategic effort, Zhuge's opponents played into his hands. Guo Huai had been ordered to join Sima Yi at Mount Qi but he took the initiative and together with Fei Yao, tried to catch Zhuge Liang in a front-rear pincer attack. Having left the defensive position, they were routed by the Shu forces. The Shu regent then went about harvesting the early spring wheat in the vicinity. Receiving the news Guo Huai was defeated, Sima Yi altered his destination and went to reinforce the loser. The Wei marshal occupied the hills east of Shanggui, but restrained from attacking. Zhuge Liang withdrew upon completion of harvest, but was caught up by Sima Yi at Hanyang, where the latter challenged Shu forces. After the vanguards briefly engaged, however, Zhuge Liang ordered a general retreat to Lucheng (鹵城), where he could set up a better defense. The Prime Minister sent his generals to station atop two mountains both north and south to his fortress, and set up "covering camps" near the riverbanks. Generals under Sima Yi requested the marshal for a showdown, which Sima was hesitant to do so. Faced with intensive criticism and incessant ridicule, the careful marshal eventually relented. In May, Sima Yi sent Zhang He to attack the southern mountain guarded by Wang Ping, while the Wei marshal marched Lucheng from the main road. Zhuge Liang ordered Wei Yan, Wu Ban, and Gao Xiang to stop Sima Yi outside the city wall, where the two forces clashed. Sima Yi suffered a heavy defeat and Zhang He could make no progress. Nevertheless, Sima Yi still possessed of a sizable army after such a defeat, and he would continue the war.

After the victory, Zhuge Liang did not capitalize with a major offensive due to a lack of food supply, while Sima Yi, having good rejuvenation, again mounted attacks on Shu, and conquered Zhuge Liang's outer camps. According to the Book of Jin, having lost his outer camps, Zhuge Liang retreated under the cover of night, but was caught up and dealt a serious blow. However the Book of Jin has been widely criticised for inaccuracies. In the Records of the Three Kingdoms, reports instead that Li Yan, who was responsible for maintaining ration supplies to the front, realizing rain had caused the breakdown of transport, lied to Zhuge Liang that Liu Shan had ordered a withdrawal.

Sima Yi, letting go of his usual cautiousness after his prior success, ordered Zhang He's cavalry to further pursue the enemy in an attempt to capitalize on their recent victory. Zhang He argued with his superior that additional risks should not be taken when they had already won, but Sima threw out his title on Zhang and forced the latter to carry out his will. Indeed, Zhang He was ambushed at Mumen, where Zhuge Liang ordered massed crossbowmen to hide at high grounds and fire at the approaching enemies when they entered a narrow defile. Zhang He was hit by a stray arrow on his right leg and died, and Sima Yi became the single most valued military authority of Cao Wei.

Fifth expedition
In the following two years both sides developed agriculture and prepared for another inevitable campaign in Longyou. Sima Yi, for his part rehabilitated the Zhengguo Canal in 234, increasing the potential to withstand a protracted war in Longyou.

In the spring of 234, 100,000 Shu soldiers advanced through the Qin Mountains by way of Baoye toward the broad plain of Wuzhang Plains, in what would become Zhuge Liang's fifth and last Northern Expedition. Sima Yi, well prepared for such a move with a 200,000-strong army, built a fortified position on the southern bank of the Wei River. The veteran of the Zhuge Liang's incursions, Guo Huai, suggested that the Shu forces were not planning an immediate attack on Chang'an itself but were planning to consolidate their position on the Wuzhang Plains for a takeover of Longyou, which had always been Zhuge Liang's immediate goal. Already, he pointed out, there were reports of Shu forces crossing the Wei River upstream and constructing lines of communications. Concerned about the threat of being cut off on the south bank, Sima Yi asked for an additional planned reinforcement of several hundred thousand troops for the communication center of Beiyuan. Such a move was none too soon, for Zhuge Liang was already on the verge of wiping out the Wei garrison after encroaching on the Wei positions in the north. After two months of manuevring north of the Wei River, the additional Wei reinforcement successfully foiled Zhuge Liang's attempt and he settled down to a stalemate on the Wuzhang Plain. The Shu army anticipated a long protracted struggle and used the tuntian system pioneered by Cao Cao, as they awaited an agreed offensive by Eastern Wu.

Sun Quan's armies in the Huai River region, however, was defeated and his offensive broke down due to the spread of endemic disease. The frustration of this last hope to break the stalemate no doubt increased the rapid deterioration of Zhuge Liang's health and depressed mental condition. By late summer, he started giving instructions to his close subordinate officers on the future of Shu. In the early autumn of 234, Zhuge Liang died at the age of 54.

Sima Yi, convinced that Zhuge Liang had died despite the fact that Zhuge's death was kept a secret by Shu, gave chase to the retreating Shu forces. Zhuge Liang's successor, Yang Yi, then turned around, pretending to strike in full scale by devastating the vanguard of Wei. Learning the news of the defeat, Sima Yi feared that Zhuge Liang only pretended he was dead to lure him out for a full scale war that favored Shu force, and immediately ordered a general retreat. Common folklore tells of a double, or a wooden statue, that was dressed as Zhuge Liang, driving Sima Yi away in this incident. In any case, word that Sima Yi fled from the already dead Zhuge Liang spread, spawning a popular saying, "A dead Zhuge scares away a living Zhongda (Sima Yi's style name)" (死諸葛嚇走活仲達). Sima Yi's answered such ridicule by claiming that he, like most of the time, could predict the intention of living Zhuge Liang, but not a ghost.

News of Zhuge Liang's death was withheld until the army had reached the safety of the Baoye valley to return to Hanzhong. Sima Yi, still fearful that the announcement was false and merely another opportunity for Zhuge to demonstrate his talent for ambuscade, hesitated to pursue. Only after his inspection of the empty Shu encampment did he resolve that pursuit was appropriate, but after reaching Baoye and deciding the advance could not be supported with supplies, the Wei army returned to the Wei River. The death of Zhuge Liang ended a huge strategic threat to Wei and the Wei court soon began development of ambitious public works.

Analysis
It is surprising that although, of the three states, Shu was the weakest in terms of land size and resources, in its early years it carried out a vigorous offensive military policy. If Zhuge Liang had not died in 234, he may well have continued this policy. However, the constant expeditions took a heavy toll on Shu's limited resources and this was worsened by Jiang Wei's Northern Expeditions after the death of Zhuge Liang. Resources wise, Shu was far inferior to the vast state of Wei, as reflected in the obvious numerical difference: with the exception of the second expedition, Shu force committed never exceeded 50% of the Wei force it faced during each campaign, and it was only Zhuge Liang's ingenuity that forced Wei to be on the defensive all the time.

Sima Yi was arguably one of the best tacticians that Wei had at that period. Even so, after initial defeats against Zhuge Liang, he was forced to change his tactics in the later expeditions. He was on the defensive for long periods of time with strong fortifications to deter Shu. His aim was to create a deadlock in which was to wait for Shu's supplies to run out and to force them to retreat without a fight. In the last expedition's deadlock on the Wuzhang Plains, Sima Yi's reluctance to engage in battle prompted Zhuge Liang to send him a woman's dress in one occasion to mock his tactics. Even so, Sima Yi refused to rise to the bait, much to the displeasure of his officers.

The diplomatic success in restoring the alliance with Sun Quan prior to the Northern Expeditions has been dismissed as useless because it brought little strategic dividend: each side had different political agendas which precluded close military coordination. Once the first Northern Expedition was turned back, the Wei state was capable of handling the two-front threat without much difficulty.

Arguments revolving around Wei Yan's plan for a surprise assault on Chang'an have never been stopped. Whether his plan could have succeeded, Zhuge Liang had rejected it, believing the plan was far too ambitious. In Zhuge's view, Chang'an, being one of Wei's most prosperous cities, would probably have been well fortified, in contrast to the intelligence from Wei Yan. Furthermore, there is little chance that the people of the city, who enjoyed peace and prosperity under the rule of Wei, would side with the Shu-Han forces. However, it may be more possible that Zhuge's military objective was to cut the connection between Longyou and Luoyang to force the surrender of the western wing of Wei, instead of attacking the heartland of Wei to "restore the Han Dynasty".

In fiction
The Northern Expeditions were featured prominently in the historical novel Romance of the Three Kingdoms by Luo Guanzhong, covering chapters 91-105 out of the 120 chapters in the novel. Many actual events were largely romanticised or highly exaggerated, while some fictitious stories were also included, for dramatic effect. See the following for some fictitious stories in the novel that are related to the Northern Expeditions:


 * Xincheng Rebellion
 * Empty Fort Strategy

Modern references
The Northern Expeditions are featured as playable stages in Koei's video game series Dynasty Warriors. As of the sixth instalment in the franchise, all of the five expeditions are playable stages in some form.