Zhuge Liang Begins the Northern Expeditions

Nanzhong was pacified.

Now Zhuge Liang looked north.

Shu Han was smaller than Wei. It had fewer people, less land, and harder supply lines.

Yet Zhuge Liang still had to attack.

If Shu claimed to restore the Han but only sat in Chengdu, the claim would slowly become empty.

The Chu Shi Biao

In 227, Zhuge Liang prepared to move the army into Hanzhong. From there, he would strike north against Cao Wei.

Before leaving, he submitted the famous Chu Shi Biao, the memorial before setting out.

He did not pretend Shu was strong. He began by saying the realm was divided in three and Yi Province was exhausted.

Then he reminded Liu Shan that loyal officials inside and soldiers outside were working because they remembered the late emperor.

In the memorial, Zhuge Liang first asked to campaign. Then he explained how Chengdu should keep running while he was gone.

Zhuge Liang urged Liu Shan to open channels of advice, reward and punish fairly, and stay close to worthy ministers while avoiding petty men. He recalled Liu Bei's three visits to the thatched cottage and the trust placed in him at Baidicheng.

He also named officials Liu Shan should consult while he was away. Some could help with palace affairs. Some could advise on government and military decisions. Rewards and punishments, he warned, should not differ between the inner palace and the outer administration.

That mattered because Zhuge Liang was leaving Chengdu for Hanzhong. If the front moved, the rear could not fall into disorder. Liu Shan was young, and the court still had its own factions. Zhuge Liang had to settle the rear before he could command from the north.

If Shu only guarded Yi Province, it would look less like the Han revived and more like a regional regime in the southwest. Zhuge Liang needed the campaign to show that Chengdu still treated Luoyang as its political destination.

By the end of the memorial, the reasons for war, the arrangement of the rear, and the people Liu Shan should trust had all been placed before the young emperor.

Wei Chose Defense First

As Zhuge Liang prepared, Wei also changed.

Cao Pi died after only a few years as emperor. His son Cao Rui became Emperor Ming of Wei.

Cao Rui initially considered attacking Shu first. Sun Zi advised caution. The roads were hard, transport would be expensive, and Wei still had to guard against Wu in the southeast.

Sun Zi was counting the cost. A campaign into Shu would require elite troops, long supply transport, and attention to the southern fronts in Jing, Xu, Yang, and Yu, where Eastern Wu might attack by water.

The total force could reach 150,000 or 160,000 men. That meant more conscription, more transport labor, and more pressure on the whole country.

Defense was cheaper. Wei could place strong commanders at dangerous passes, hold the entrances, let the soldiers rest, and spare the people a new round of heavy labor.

Cao Rui accepted a defensive posture.

He also gave Sima Yi authority over military affairs in Jing and Yu and stationed him at Wancheng.

Wei did not rush into the mountains. It put a patient commander near the line.

Sima Yi Approaches the Front

Sima Yi had once avoided Cao Cao's summons by pretending to be ill. Cao Cao later forced him into service and warned Cao Pi that Sima Yi had ambitious bones.

Sima Yi came from the Sima clan of Henei. His father Sima Fang had served as Intendant of Jingzhao. Sima Fang had eight sons whose courtesy names all included the character da, so people called them the "Eight Da of the Sima clan." Sima Yi was the second son, courtesy name Zhongda.

When he was young, his reputation reached Cao Cao. Cao Cao wanted him to serve in the office of the Minister of Works. Sima Yi saw the Han declining and did not want to enter Cao Cao's service, so he claimed to be ill and unable to rise.

Cao Cao did not fully believe him. Later, when Cao Cao summoned him again, the message became harsher. If Sima Yi kept delaying, he would be arrested. Sima Yi finally entered service.

Cao Pi trusted him anyway.

After Cao Pi became emperor, his reliance on Sima Yi deepened. When Cao Pi campaigned against Wu, he often left Sima Yi in the capital and entrusted government affairs to him.

Before his death, Cao Pi named Sima Yi among the regents who would assist Cao Rui. He also warned the young heir not to believe people who tried to turn him against them.

By Cao Rui's reign, Sima Yi was becoming one of Wei's most important commanders. He was not yet Zhuge Liang's main opponent in every battle, but he was moving closer to that role.

Meng Da Failed

Zhuge Liang also tried to use Meng Da.

Meng Da had defected from Shu to Wei and had been treated well by Cao Pi. After Cao Pi died, his support weakened. His relationship with Sima Yi was poor.

Zhuge Liang secretly wrote to him, urging him to return to Shu.

Xincheng, where Meng Da was stationed, sat in a sensitive position near the borders of Wei, Shu, and Wu. If Meng Da rebelled, he could disturb Wei's southeastern defenses and give Zhuge Liang a point of support away from the main western route.

Meng Da hesitated. The matter was then reported by Shen Yi, who had his own conflict with him.

Sima Yi responded with both deception and speed.

He first wrote to reassure Meng Da that Wei did not suspect him. He told Meng Da that Wei had treated him well, and that if Zhuge Liang wanted to help him, he would not have leaked the news of his rebellion.

Meng Da wavered again. He had been contacting Shu, but he still did not dare cut himself off from Wei.

Meng Da had assumed that Sima Yi would need to report to court and wait for orders. Instead, Sima Yi reached Xincheng in eight days.

Some of Sima Yi's own officers urged caution. Meng Da had contact with both Wu and Shu, and reinforcements might come.

Sima Yi judged the moment differently. Meng Da, he said, had no firm loyalty and had not made up his mind. That was exactly when he had to be struck.

The city fell. Meng Da was killed.

Zhuge Liang lost a possible eastern support point. The campaign's main hope now shifted west.

Wei Yan's Ziwu Valley Plan

Zhuge Liang then focused on the western route.

Wei Yan proposed a bold plan.

He wanted five thousand elite troops and five thousand men's supplies. He would move through Ziwu Valley and strike Chang'an directly. If Xiahou Mao panicked and fled, Wei Yan could take the city before Wei reacted. Zhuge Liang could then come out through Xie Valley to support him.

It was risky but tempting.

Ziwu Valley was an old road through the Qinling Mountains. It connected Hanzhong in the south to Guanzhong in the north. It was shorter than the safer routes, but it was narrow, steep, and hard for marching, supply, and retreat.

Wei Yan had reason to think boldly. Liu Bei had trusted him with Hanzhong, one of Shu's most important military positions. He was brave, experienced, and eager to use surprise.

His target was Xiahou Mao, a Cao clan relative and imperial in-law, but not a famous battlefield commander. If Shu troops suddenly appeared near Chang'an, Wei Yan believed the city might panic.

If Chang'an panicked, Wei Yan could use its stores and the grain left by fleeing people to hold out. By the time Wei assembled forces from the east, Zhuge Liang's main army might have arrived through Xie Valley.

Zhuge Liang refused.

He preferred a steadier route through Qishan, hoping to win over the Longyou region before pressing east.

Later generations argued over this choice. Zhuge Liang's decision at the time was clear: the valley route was too dangerous, and the broader road toward Longyou was more controllable.

Jieting

Zhuge Liang used Zhao Yun and Deng Zhi as a diversion in Ji Valley, drawing Cao Zhen's attention.

He led the main force toward Qishan.

Wei was shaken. Tianshui, Nan'an, and Anding responded to Shu. Guanzhong became anxious.

Cao Rui went to Chang'an and sent the veteran Zhang He to fight.

Cao Rui's presence helped steady the situation. The battlefield responsibility fell to Zhang He.

Zhang He was an old commander from Cao Cao's generation. By this point many of Wei's earlier famous generals were gone. For the western front against Zhuge Liang, he was one of the most important men Wei could send.

Jieting became the key.

Zhuge Liang did not send Wei Yan or Wu Yi as the vanguard. He chose Ma Su, whose talent he valued even though Liu Bei had warned that Ma Su spoke beyond his real ability.

Ma Su loved to discuss military plans. His ability impressed Zhuge Liang, and during the Nanzhong campaign Zhuge Liang had accepted his advice to attack the heart rather than only attack cities.

But knowing how to talk about war was not the same as holding a decisive position under pressure.

Ma Su disobeyed instructions and camped on high ground, away from water.

Wang Ping urged him not to do it. Ma Su refused.

Zhang He cut off the water supply and attacked. Ma Su's army collapsed. Jieting was lost.

Zhuge Liang had no forward base and withdrew to Hanzhong.

Wang Ping kept part of the army together by beating drums and holding position, making Zhang He suspect an ambush. The famous "empty fort" story later attached to Zhuge Liang is closer in historical spirit to Wang Ping's calm after Jieting.

The first Northern Expedition had shaken Wei, but it failed.

After the Withdrawal

Ma Su's failure at Jieting was the direct cause. Zhuge Liang executed him, submitted a memorial taking responsibility, and asked to be demoted. He was reduced to General of the Right, though he still carried out the work of the chancellor.

Wang Ping, by contrast, rose in Zhuge Liang's estimation because he had held troops together in defeat.

The first Northern Expedition ended without Chang'an, without Luoyang, and without a breakthrough into the Central Plains. The same problems remained: Shu was smaller, the roads were hard, supplies were difficult, and Wei could react.

But the expeditions would not stop.

Next, the campaigns continue, and Sima Yi becomes harder to avoid.