In the sixth year of Jiaping (254), Sima Shi deposed the Wei emperor Cao Fang and installed Cao Xin, the Duke of Gaoguixiang, as the new emperor. The following year, Sima Shi personally led an army to quell the rebellion of Yiqiu Jian and Wen Qin. However, on the way back, Sima Shi died of illness at the age of forty-eight and was posthumously known as "Zhongwu". Before dying, he handed over power to his younger brother Sima Zhao, which is in line with the tradition of "brother and brother". When Sima Zhao's son Sima Yan ascended the throne, the Eastern Jin Dynasty also experienced four "brothers and brothers" situation, one of which occurred in the Western Jin Dynasty and three times in the Eastern Jin Dynasty.
The first is Sima Zhi and Sima Chi. Sima Xin was the second emperor of the Western Jin Dynasty, the second son of Sima Yan, the emperor of Jin Wu, and his mother was Yang Yan, the empress of Wuyuan. He was crowned crown prince in the third year of the Tai dynasty (267 AD), and then formally succeeded to the throne as Emperor Hui of Jin in the first year of Taixi (290 AD). However, he did not achieve significant results during his reign, and the famous "Yongjia Rebellion" occurred, which accelerated the decline of the Western Jin Dynasty. In the end, Sima Chi succeeded to the throne as the crown prince and ascended the throne after Sima Zhi's death.
Next came Sima Yan and Sima Yue. Sima Yan was the third emperor of the Eastern Jin Dynasty and the eldest son of Sima Shao, the Ming Emperor of Jin. He ascended the throne in the third year of Taining (325 AD), but due to his young age, his mother Yu Wenjun became regent. After Sima Yan's death, he was succeeded by his younger brother Sima Yue, who died after only two years of reign. This frequent turnover accelerated the decline of the Eastern Jin Dynasty, and the Shi clan gate gradually seized real power.
Then came Sima Pi and Sima Yi. Sima Pi was the sixth emperor of the Eastern Jin Dynasty and the eldest son of Sima Yan, the emperor of Jincheng. During his reign, there was turmoil in the country, and Murong forces in the north continued to invade, leading to the increasing decline of the Eastern Jin Dynasty. In the end, Sima Pi died, and since he had no heirs, Chu Garlic issued an edict after the temple and was succeeded by Sima Yi. Although Sima Yi succeeded to the throne, he reigned for only six years before he was eventually deposed and demoted to the title of King of the East Sea.
Finally, Sima Dezong and Sima Dewen. Sima Dezong was the tenth emperor of the Eastern Jin Dynasty, the eldest son of Sima Yao, the Xiaowu Emperor, and the half-brother of Emperor Gong Sima Dewen. During Sima Dezong's reign, the country was in turmoil and the state was weakening. Eventually, he was killed by Liu Yu in 419 at the age of 37. Liu Yu intended to proclaim himself emperor, but because the time was not ripe, he made Sima Dezong's younger brother Sima Dewen emperor and changed Yuan to Yuanxi. However, soon after, Sima Dewen was also assassinated at the age of 36.
In short, the four "brothers and brothers" in the history of the Jin Dynasty did not save the decline of the country, but accelerated the demise of the Western Jin and Eastern Jin Dynasties.