In 237 AD, Gongsun Yuan, the leader of the Gongsun family, who had dominated Liaodong for nearly fifty years, openly rebelled against Wei, established himself as the King of Yan, and established hundreds of officials. This made Emperor Wei Ming very angry, and quickly recalled Sima Yi, who was fighting against the Shu Han army on the front line, and Sima Yi promised Emperor Wei Mingdi to sweep Liaodong within a year, mainly considering that the marching liaodong was a long distance, and it would take half a year to go back and forth. After Sima Yi led an expedition and won successive battles, Gongsun Yuan, under Sima Yi's crusade, had no power to fight back, and was defeated within two months, and the Gongsun family, the last divided force at the end of the Eastern Han Dynasty, was destroyed.
Under Sima Yi's crusade, the Gongsun family, which owned several counties in Liaodong, was simply hanged and looked weak. This was first of all due to Sima Yi, who was able to compete with the elite Shu Han led by Zhuge Liang on the Shu Han front, and did not fall behind, and Sima Yi's military ability was beyond doubt; secondly, the Wei state's crusade this time was well prepared, the soldiers were well fed, and the morale of the troops was high; and finally, Gongsun Yuan had the ambition to be king, but he did not have the ability to command, and defeat was the inevitable result. After this battle, Gongsun Yuan defeated the Gongsun family's fifty years of painstaking management of Liaodong.
The Gongsun family was defeated in the civil war, but this family's achievements in fighting foreign enemies were quite brilliant, and it can be said that it was the absolute hegemon of the Liaodong region.
At that time, Liaodong, the most powerful nation, was the Goguryeo that appeared repeatedly in the history of the Sui and Tang Dynasties and performed quite strongly. It should be known that the two dynasties of The Sui and Tang Dynasties, the five generations of emperors, starting from the Sui Wen Emperor Yang Jian, going through the Sui Emperor, Tang Taizu and Tang Taizong, and then to the last Tang Gaozong, were all happy to use troops against Goguryeo tirelessly, until Tang Gaozong finally destroyed Goguryeo. The demise of the Sui Dynasty was not unrelated to the Sui Emperor's three eastern expeditions to Goguryeo. It can be seen that Goguryeo is a very difficult bone to gnaw.
Goguryeo was already a relatively powerful nation when Gongsun Du, the founder of the Gongsun family, ruled Liaodong. Goguryeo was fierce, belligerent, and fond of looting, with a total of 30,000 households at the time. The Gongsun family, when it was destroyed by Sima Yi, was only 40,000 households, and the two forces could be described as equal opponents.
At the end of the Eastern Han Dynasty, Goguryeo took advantage of the division of the Central Plains and the political chaos to repeatedly invade the liaodong border, causing the people there to suffer unspeakable. Such a leisurely day, after the arrival of Gongsun Du, is gone forever. In 190 AD, Gongsun Du became the Taishou of Liaodong, beginning the Gongsun family's rule over Liaodong for nearly fifty years. As soon as Gongsun Du took office, he calmed down the disobedience to him internally and expanded his external strength, and at first Goguryeo was shocked by his power and sent troops to help Gongsun Kang pacify the other tribes. However, the Goguryeo people were difficult to move by nature, and still harassed Liaodong from time to time, and as a result, Gongsun Du personally led an army and defeated Goguryeo.
During the reign of Gongsun Du's son Gongsun Kang, goguryeo was difficult to change. In 209, Gongsun Kang took advantage of the death of the Goguryeo king Bogu and the internal power struggle, and invaded Goguryeo in one fell swoop, breaking through the capital of Goguryeo in one fell swoop, forcing Bogu's eldest son Baqi to surrender. The Gongsun family was the absolute nemesis of the arrogant Goguryeo kingdom of that era. Unfortunately, after the demise of the Gongsun family, the Central Plains Dynasty experienced the most frequent dynastic changes in Chinese history (the Three Kingdoms, two Jin Dynasties, the Sixteen Kingdoms, the Southern and Northern Dynasties), and Goguryeo took advantage of the situation to rise again, becoming the bitter lord who plagued the Sui and Tang dynasties for several generations of emperors.