Preface.
History is long and unpredictable. Among them, the struggle between emperors, the struggle is deceitful, and the strategy and loyalty dance together. In the process of the rise and fall of the Southern Song Dynasty, Liu Yu laid out a journey of the Warring States in a tragic historical picture. Normally, the new monarch would purge hostile forces after seizing power, but few people treated the enemy's family with the same determination as Liu Yu did. This raises the question of why he acted in such a way and whether he did not care about the name of benevolence
Dong Zhuo held the imperial power hostage, and the Central Plains was in turmoil. Cao Cao responded to the crisis and saved the country. However, after Cao Cao's death, Cao Pi usurped the throne, and Sima Yi silently seized political power. He skillfully helped Cao Pi successfully seize the crown prince's throne, so that the Cao family became the ruler of the north on behalf of the Han dynasty. Under the wisdom of Sima Yi, the Cao dynasty came to prominence. However, the situation changed drastically, and Cao Wei's internal power struggles continued. Sima Yi's descendants continued to control the government, and after the Gaopingling Rebellion, the Sima clan completely dominated the Wei state.
After Sima became emperor, he continued to unify the world. Cao Pi's power gradually declined, and the world was in turmoil. After the establishment of the Eastern Jin Dynasty, Liu Yu recovered the lost land south of the Yellow River through the Northern Expedition, and finally deposed the Eastern Jin Dynasty, proclaimed himself emperor in Jiankang, and established Liu Song. However, Liu Yu did not stop there, and he took extreme measures to purge the remnants of the Sima clan in order to ensure the stability of the country. This clan punishment and men's torture became a tragic and necessary scene in history.
Epilogue. 
Although Liu Yu's cruel decision has been controversial in the long course of history, considering the current situation in which he lived, it may be for the long-term peace and stability of the country, and he will do whatever it takes. This decision completely wiped out the Sima clan and laid a solid foundation for the establishment of Liu Song. In the changes of history, every strategist and general is performing their own scenes, and Sima Yi and Liu Yu, the two great men, have undoubtedly contributed a chapter in the annals of history.