The so-called wall head grass refers to people who are good at changing their positions with the situation, and there is no shortage of such wall head grass during the Three Kingdoms period, such as Lü Bu, such as the Xuzhou head snake Chen Jue and Chen Deng's father and son, and the Shen Tan and Shen Yi brothers who occupy the three eastern counties, and the Three Kingdoms wall head grass Meng Da: three rebellions in life, the last pit was Zhuge Liang.
<h1 class="pgc-h-arrow-right" data-track="2" > first: betrayal of Liu Zhang</h1>
Meng Da was a native of Fufeng County, a fellow of Fazheng, the two served together under Liu Zhang's command in Yizhou, and the relationship was quite good, in 208, after Yizhou did not drive Zhang Song to make Cao Cao despised and returned to Yizhou, he urged Liu Zhang to marry Liu Bei, Zhang Song and Fa were friends, Fa Zheng was depressed in Yizhou, so the two had another choice to turn to Liu Bei, in 211 Liu Zhang, facing pressure from Cao Cao and Zhang Lu in Hanzhong, invited Liu Bei to enter the river under the strong leadership of Zhang Song, and sent Fa Zheng and Meng Da to meet Liu Bei.
Fa is Zhang Song's friend, Meng Da is also Fa Zheng's friend, plus Meng Da is estimated not to be reused in Yizhou, so Meng Da also took the same step forward as Fa Zheng and surrendered to Liu Bei, which was Meng Da's first betrayal, after Liu Bei entered Yizhou, he rewarded his merits and deeds, and sealed Meng Da as Yidu Taishou.
<h1 class="pgc-h-arrow-right" data-track="5" > second time: betrayal of Liu Bei</h1>
In May 219, Liu Bei won the Battle of Hanzhong, in June Meng Da attacked Fangling in the Eastern Three Counties from Zigui, and Liu Fenghui and Shangyong from the middle of the Han Dynasty, and took the Eastern Three Counties in one fell swoop, but in 220 Meng Da led more than 4,000 families to surrender to Cao Wei, and there were three main reasons why Meng Da wanted to betray Liu Bei:
1. In 219, Guan Yu was defeated and killed in the Battle of Xiangfan, during the great war Guan Yu asked Liu Feng several times to send troops to cooperate with his military operations, Liu Feng originally intended to send troops at first, but under the persuasion of Meng Da, he refused to send troops on the grounds that he had just taken the eastern three counties and his people's hearts were not yet dependent, although this was not the main reason for Guan Yu's defeat, but Meng Da was afraid that Liu Bei would settle accounts after autumn.
2. Liu Feng is the main general of the three counties of Zhenshoudong, Meng Da is his deputy general, the relationship between the two is not harmonious, Liu Feng even looks at Liu Bei's encouragement of Meng Da to take it for himself, which is another reason why Meng Da has a bad idea.
3. As mentioned above, meng da and Fa Zheng have a relationship with each other, Fa Zheng has a very high status within the Shu Han clique, is The Shang Shu Ling of Liu Bei's Han Kingdom, and his status can almost be on a par with Zhuge Liang, but unfortunately Fa Zheng died at this time, originally there was a Fa Zheng, even if Liu Bei wanted to settle accounts after the autumn, it would not be too difficult for Meng Da, and now Fa Zheng died in the middle of no one to speak for Meng Da, plus Zhuge Liang's brother-in-law Fang Ling tai shou Pu Qi died at the hands of Meng Da, so Meng Da simply surrendered to Cao Pi in fear.
<h1 class="pgc-h-arrow-right" data-track="10" > third time: betrayal of Cao Rui</h1>
Although Cao Pi was careful, he was still very good to the generals, and Meng Dalai gave Cao Pi a very high treatment, not only made him a general of The Scattered Horse Changshi, a general of Jianwu, and the Marquis of Pingyang Ting, but also combined the three counties of Fangling, Shangyong, and Xicheng into Xincheng County, appointed Meng Da as the Taishou of Xincheng County, and handed over the defense of Cao Wei's southwest direction to Meng Da, but with the death of Cao Pi, who was very important to him, and the death of Xiahou Shang, the head of the Jiuqing Who had a good relationship with him, and the general Xiahou Shang, the general of Zhengnan, Meng Da lost several of his biggest patrons in the Cao Wei Dynasty. It happened that at this time, Zhuge Liang, the chancellor of the Shu Han Dynasty, was plotting the Northern Expedition and sent people to secretly contact Meng Da to return to Shu Han, so Meng Da betrayed again, but this time his opponent was the scheming Sima Yi, who marched on the road and drove from Wancheng to Shangyong in only eight days, hitting Meng Da by surprise and quelling Meng Da's rebellion in advance.
Meng Da's third and final rebellion pitted Zhuge Liang, because the strategic position of the eastern three counties was extremely important: the north could attack Guanzhong, the east could enter the Xiangfan line under Cao Wei's control, and the defeat of Meng Da's army was the beginning of Zhuge Liang's first Northern Expedition, and the reason why Zhuge Liang secretly contacted Meng Da in advance was to want Meng Da to send Meng Da troops out of the eastern three counties to plan his own military operations, and it is conceivable that if Meng Da succeeds in rebelling against Wei, whether it is going north or east, Zhuge Liang's chances of victory will be much greater, and the first Northern Expedition Zhuge Liang is fully prepared. At the beginning of the campaign, considerable results were achieved, three of the five counties of Longyou fell into the hands of Shu Han, and the Wei Ming Emperor Cao Rui even personally marched to Chang'an, at this time Meng Da sent troops to definitely contain Cao Wei's troop deployment, the first Northern Expedition with Meng Da's strategy Zhuge Liang or will achieve great results, but Meng Da's defeat all this has become a bubble, it can be said that Meng Da did pit Zhuge Liang.