Among the three kingdoms of Wei Shu and Wu, the most eager to complete the unification was the weak Shu Han, and the most powerful to complete the unification was the powerful Cao Wei, but no one expected that the three kingdoms of Wei Shu and Wu had fought each other for decades, but let Sima Yi's family for three generations reap the benefits of the fisherman, successfully annexed the Cao Sun Liu Sanjia, and established the fourth great unified dynasty after Qin and the two Han Dynasties (including the new dynasty), the Western Jin Dynasty.
When Cao Cao was a chancellor, he heard that Sima Fang's second son Sima Yi was very talented, so he recruited him to be his subordinate official, although Sima Yi tried his best to cover up his own sharpness, but still let Cao Cao, who knew people well, see the "wolf care of the face", and predicted that Sima Yi would never live under the people for a long time, and it would be a big disaster for Cao in the future.
Cao Cao was cunning by nature, but he was unexpectedly deceived by Sima Yi, a more cunning offspring, and did not kill this hidden danger in his mouth until his death. At that time, Sima Yi had no soldiers and no power, and it seemed difficult to pose a threat to Cao Wei in the encirclement of the Cao clan.
However, the strong advance of Shu Han and the sudden rebellion of Meng Da achieved Sima Yi's magnificent turn from a civilian to a general, and by killing Meng Da and repelling Zhuge Liang's many northern expeditions, Sima Yi successfully grasped the power of Yongliang's army. If the confrontation with the Shu Han Dynasty was the first step in the rise of Sima Yi's father and son, the first regime to be destroyed in the Three Kingdoms was Sima Yi's fangs.
As we all know, the Shu Han was the first to perish in the Three Kingdoms, but in fact, before the Shu Han, there was another regime that was first pacified, and this regime was Gongsun Yuan's Yan State. Gongsun Yuan was a large clan of Liaodong in the generation, first dependent on Cao Wei shi to guard Liaodong, and later to Eastern Wu, and the strength was not strong, so usually we only count the three kingdoms of Wei Shu and Wu, not the four kingdoms of Wei Shu and Wu Yan.
In 237, Gongsun Yuan, who considered himself Emperor Yuan of Shangao, established himself as the King of Yan. However, at this time, the population of the Yan state was only 300,000, and the number of troops that could be used was only tens of thousands. Gongsun Yuan once thought that the road was far away, and with Sun Quan coming to the aid of the sea, the State of Wei would not dare to attack. However, he did not expect that Sima Yi led 40,000 Wei troops to attack the city for a long time, and three battles and three victories broke through Xiangping, and Gongsun Yuan was killed in horror.
However, after the destruction of the city, Sima Yi still did not stop, and he slaughtered more than 7,000 men over the age of 15 in the city to build the Jingguan. More than 2,000 officials below the secretary of state served by Gongsun Yuan and Gongsun Yuan were beheaded, and a large number of ordinary people were relocated to the Central Plains, and the elite accumulated in Liaodong for decades was destroyed overnight.
This brutal move of Sima Yi caused serious damage to Liaodong, which had a limited population, and Liaodong was then transferred to Youzhou. Due to the artificial creation of a "vacuum" zone, the "Pandora's Box" was opened.
Goguryeo, which was originally entrenched in the east of Liaodong, took advantage of the rise. This Goguryeo was originally an ethnic county under the rule of Xuanju County in the Western Han Dynasty, and the main population was The People of The Bulge and the Buyeo. During the internal strife of the Han Dynasty, it took the opportunity to establish a political power, but due to the large population of the Han Dynasty border counties, Goguryeo always submitted to the Central Plains. Gongsun Yuan was not strong, but he was still able to suppress Goguryeo.
However, after the destruction of Liaodong, Goguryeo began to grow and attack the Wei border. Youzhou had to set out on an expedition from Youzhou, and although he successfully defeated Goguryeo, it exposed the hidden danger that Bian County was no longer able to suppress Goguryeo. Sure enough, less than 50 years after the founding of the Western Jin Dynasty, the Central Plains were once again in chaos.
By the time the Sui Dynasty reunified Hainei, Goguryeo, after 400 years of development, had a crowd of 5 million, becoming a major country in Northeast Asia, directly threatening the sui Dynasty's northeastern territory. The Sui Emperor issued a sigh of "do not leave your descendants to worry", and used millions of troops to conquer three times, but suffered defeat.
The subsequent Tang Dynasty went through three generations of monarchs, Li Yuan, Li Shimin, and Li Zhi, and it took 50 years to finally completely destroy Goguryeo in 668 AD, eliminating this great trouble.