In 226, Emperor Wen of Wei died, and the Wei Ming Emperor Cao Rui took the throne, and Cao Zhen, Cao Xiu, Chen Qun, Sima Yi and other Cao Wei ministers were appointed to assist Emperor Ming. The following year, Zhuge Liang, the chancellor of the Shu Han Dynasty, wrote a book entitled "Table of Teachers", requesting Liu Chan to go north to the Wei state and unify the Central Plains. In fact, from the perspective of the situation at that time and the future generations, this is not the best time for the Northern Expedition.
First of all, Emperor Ming of Wei's 22-year-old ascension to the throne was not "the lord of the country", and some of the civilian and military generals who followed Cao Cao and Cao Pi to fight the world were still alive, such as Chen Qun, Sima Yi, Zhang Guo, Man Yu, Cao Zhen, Cao Xiu, Xiahou Ba, etc., which was not in line with Longzhong's proposal to "then wait for the world to change and take the Central Plains".
Secondly, the State of Wei was the largest in size and the strongest in economic strength, and only Yi Prefecture remained in the Shu Han Dynasty since Guan Yu lost Jingzhou, and most of the counties in the southern central region were mixed with ethnic minorities, and the population was only one-fifth of the State of Wei and one-third of that of Eastern Wu.
In addition, the Battle of Yiling suffered heavy losses, the rebellion in South Central had just been quelled, the military generals who could recruit good warriors had long since withered away, and only a few generals such as Zhao Yun, Wei Yan, and Liao Hua were left with experience in leading the army;
Finally, Emperor Ming of Wei heeded the advice of Sun Zi, an old minister of Cao Wei, and made defensive preparations, sending large armies to garrison Guanzhong and at the same time developing his own economy in order to trap the Shu Han and Eastern Wu states.
In 227, Zhuge Liang ordered Zhang Yi to join the army as Chancellor Changshi and Jiang Huan to assist in handling state affairs, and sent Zhao Yun and Deng Zhi to lead the division to jigu to attract the main force of the Wei army, and led the main army from Hanzhong to besiege Qishan. The Wei Ming Emperor Cao Rui personally sat in Chang'an, and sent the general Cao Zhendu to supervise the right armies of Guan, to break Zhao Yun's men and horses at Jigu Valley, and the left general Zhang Guo and the governor of various roads and horses to meet the Shu Han army at the street pavilion.
Guo Huai of Wei, Taishou MaZun of Tianshui County, Jiang Wei, Gongcao Liangxu, Yin Reward, and Liang Qian, the chief secretary, went out on a tour, and suddenly it was rumored that the Shu Han army was coming, Guo Huai and Ma Zunwenxun fled, Jiang Wei, Liang Xu, Yin Xiang, Liang Qian, and the three counties of Nan'an, Tianshui, and Anding returned to Shu Han, and only the Wei state of Longxi County's Taishou Youchu made the Shu army retreat by delaying the army.
On the Qishan front, Zhuge Liang did not heed the suggestions of the generals and appointed the Zhenbei general Wei Yan and the Guanzhong governor Wu Yi as the main generals, but instead used Ma Mo and Wang Ping, who had performed outstanding performance in the southern and central quelling, to go to the street pavilion to resist Zhang Gao's army. According to historical records, Ma Mo disobeyed Zhuge Liang's instructions at the street pavilion and did not listen to Wang Ping's persuasion, abandoning the water source to camp on the mountain, and then breaking the Wei army with a condescending posture, only giving Wang Ping 5,000 men and horses to garrison the street pavilion. Zhang Hao led a large army to the street pavilion, and immediately sent troops to cut off the water source and grain road on the mountain, firmly trapping ma Chen's army in the mountain and setting fire to the mountain. Soon, the Shu army was hungry and thirsty, the army was scattered, Zhang Gao took advantage of the general attack, and the Shu army was defeated and retreated to Hanzhong. Zhang Gao led an army to quell the rebellion in Nan'an, Tianshui, and Anding counties.
After the war, due to the Battle of Jieting, Zhuge Liang beheaded Ma Mo, Zhang Xiu, Li Sheng, and others, and deposed Huang From Attacking. Cao Zhen, the governor of the State of Wei, in view of the defeat of the Shu Han army at Qishan, burned the Jigu Trail when Zhao Yun's troops retreated, and predicted that the next time he would definitely target Chen Cang, he sent Hao Zhao, Wang Sheng, and other troops to garrison.
Eastern Wu and Cao Wei fought at Shiting, and in order to alleviate the pressure on the State of Wu, Zhuge Liang envisioned the emptiness of Guanzhong, so he prepared a month's worth of grain and grass and led a large army to disperse Guanguan and besiege Chen Cang. The Wei general Hao Zhao refused Shu Han's surrender, and attacked such as the great cloud ladder, chongche, well, and tunnel, and held out for more than twenty days, and the division of troops to attack Yu County was also unsuccessful, and finally Shu Han's grain was exhausted, and Cao Wei's reinforcement Wang Shuang pursued to the Qinling Mountains, where he was ambushed and died.
Zhuge Liang sent Chen Shi to capture Wudu and Yinping Counties, and led a large army out of Hanzhong with the intention of building a new Hancheng and Lecheng to strengthen the defense of Hanzhong. The following year, Emperor Ming of Cao Wei sent Sima Cao Zhen the Great, the general Zhang Guo (張郃) the General of the Western Expedition, the general Sima Yi (司馬懿), the Yongzhou Assassin Shi Guohuai (雍州), and the later general Fei Yao (Fei Yao) to cut down Shu in four ways. Zhuge Liang dispatched Wei Yan and Wu Yixi into Qiangdi to repel Guo Huailong's right army, and the general Li Yan supported Hanzhong, and finally the main army Cao Zhen was trapped in the Meridian Road due to heavy rain, and Emperor Wei Ming ordered all the troops to retreat.
The Shu Han army once again marched from Hanzhong to Qishan, at this time Cao Zhen, the governor of Cao Wei, was seriously ill, and Sima Yi, who was in Chang'an, sent Fei Yao and Dai Shu to refuse to defend Tianshui, and personally led the generals to Qishan. Zhuge Liang ordered Wang Ping to besiege Qishan, and the unified army entered Tianshui to break fei Yao's troops, snatched Cao Wei's wheat and returned to Shihaocheng.
Sima Yi led his army to the city of Halo, dug trenches and camped only to encircle and not attack. Shu Han challenged several times, but Sima Yi could not hold out, causing dissatisfaction and ridicule among the generals. Faced with heavy pressure, Sima Yi had to personally lead a large army to attack, and the Shu Han Wei Yan, Wu Ban, and Gao Xiang divided their troops to meet the battle, breaking the Wei army and killing more than 3,000 people. After this battle, Sima Yi could not hold out, and as the Shu army ran out of food, Zhuge Liang once again withdrew. Sima Yi did not heed the dissuasion and forced Zhang Gao to lead an army in pursuit, resulting in Zhang Gao's death by an arrow in the wooden doorway.
After three years of rest, Zhuge Liang led a large army out of the valley mouth and arrived at Wuzhangyuan on the south bank of Weishui, confronting Sima Yi's army across the river. Before the war, Guo Huai predicted that shu Han would seize the north bank of the Wei River in the next Northern Expedition, so he had already made preparations. The two sides confronted each other for more than 100 days, during which the Weishui River rose sharply, and Sima Yi took the opportunity to sneak into the shu army meng Yan's troops, but was repelled by Zhuge Liang building a pontoon bridge with a strong crossbow.
After that, there was no more war between the two sides, and in August of the same year, Zhuge Liang died of illness in the camp, and the secretaries of the Shu and Han armies were not mourned, and the chief official Yang Yi rectified the army and horses and calmly retreated. Sima Yi learned from the local people and led his army in pursuit, Jiang Wei and Yang Yi returned to attack, and Sima Yi thought that it was a good plan and retreated. Therefore, after the Shu army entered the Xie Valley, the obituary was reported to the funeral, and Sima Yi fang knew the plan, and this matter was also used as a joke by the State of Wei as a joke and spread that "the death of Zhuge scared away Sheng Zhongda".
From 227 to 234, Zhuge Liang's five Northern Expeditions were almost fruitless, except for the first Northern Expedition to the three counties of Nan'an, Tianshui, and Anding, which fell in the wind and was soon recovered by Zhang Gao. The Third Northern Expedition captured Wudu and Yinping Counties, which were already sparsely populated due to years of conquest in Hanzhong, and had no economic value.
The first Northern Expedition abandoned Zhao Yun, Wei Yan, Wu Yi and other former emperors and generals, but used inexperienced or humble Ma Tan and Wang Pingren, resulting in a major defeat at jieting, which had a great impact on the morale of the Shu Han army and people.
In addition, Shu Han's intelligence work was almost zero, and the Second Northern Expedition to attack Chen Cang and the fifth Northern Expedition to reach the north bank of Weishui had long been recognized and prepared by Cao Wei. So much so that Zhuge Liang originally thought that Chen Cang was dilapidated and unguarded, until the army approached the city, he found that he did not expect to personally command tens of thousands of elites, and carry a large number of siege machinery, but he could not break through Chen Cang, which Hao Zhao's thousands of people were firmly defending.
Therefore, the Northern Expedition in the real sense was mainly the first, the second was mainly to cooperate with the strategy of Eastern Wu, after the three Northern Expeditions captured Wudu and Yinping, they mainly faced Cao Wei's four-way cutting of Shu, and the fourth and fifth Wei and Shu armies successively confronted Qishan and Weishui, and there was almost no large-scale battle.
However, under the administration of Zhuge Liang, shu Han attacked the Northern Expedition five times in a single prefecture, repeatedly defeating Cao Wei's army, creating a situation in which the weak prevailed over the strong. The Book of Jin records that "every time Zhuge Liang entered KouGuanzhong, the border troops could not subdue the enemy, and the Chinese army rushed to the battlefield, and it was impossible to take the opportunity", "Every large army was requisitioned, more than half of the troops were transported, and the merit was huge hundreds of millions". It was during the war with Shu Han that Sima Yi gradually gained real power, forced Zhang Guo to pursue and die, gradually eliminated dissidents and finally launched the Gaopingling Rebellion, paving the way for the Sima family to seize the world.