In the late Three Kingdoms period, Sima Yi, a major minister of Cao Wei, rose strongly and gradually grasped the military and political power of Cao Wei. After sima yi, sima shi, and sima zhao, in 265, Sima Yi's grandson Sima Yan seized the throne, established the Western Jin dynasty, and realized the unification of the world. In fact, as early as the last year of the Qin Dynasty, Sima Yi's ancestors were already very prominent, but their luck was too bad and they were killed by Xiang Yu, so what was going on?
According to historical records, one of the "Five Emperors", Zhao, had a son named Chongli, who served as a Xia official Zhu Rong during the Emperor Zhao period, also known as Huozheng. Since then, Chongli's descendants have been holding this official position through Tang Yao, Yu Shun, Xia Dynasty, and Shang Dynasty. During the Zhou Dynasty, xia officials were renamed Sima (司馬). During the reign of King Xuan of Zhou, Cheng Boxiu's father led the army for meritorious service in battle, and was praised by King Xuan of Zhou, "Xi is an official family, so it is a clan", and since then it has been changed to Sima Shi.
In the last year of the Qin Dynasty, Chen Sheng and Wu Guang revolted in Dazexiang, after which Chen Sheng sent Wu Chen to lead 3,000 people to attack the homeland of the Zhao state. With the assistance of Zhang Er and Chen Yu, the wuchen progressed very smoothly, and the team quickly expanded to tens of thousands of people and conquered more than a dozen cities. After that, the warlords adopted the strategy of Pu Tong and surrendered more than thirty cities. In the process, Sima Wei, a descendant of Cheng Boxiu's father, also defected to Wu Chen.
Sima Wei led an army to occupy Chaoge, made military achievements, and became a general of the Zhao state. Later, Wu Chen was killed, but Sima Wei remained loyal to the Zhao state and served The King of Zhao. In 207 BC, Xiang Yu led a large army to victory in the Battle of Julu, annihilating the main force of the Qin army in one fell swoop. Sima Wei, as a general of the State of Zhao, then followed Xiang Yu in battle against the Qin army, and he even almost entered the pass in front of Liu Bang, "When Zhao Bei sent Sima Weifang to cross the river into the pass, Pei Gong Nai attacked Pingyin in the north and cut off the river."
In 206 BC, Xiang Yu led a large army into Guanguan, and in Guanzhong were divided into kings, Liu Bang was made the King of Han, and Sima Wei was also crowned as the King of Yin for "fixing Hanoi and counting meritorious deeds". However, Sima Wei's territory was not large, there was only one Hanoi County, and the capital was Chaoge. Originally, King Huai of Chu agreed that whoever entered Guanzhong first could be crowned king in Guanzhong. Liu Bang was supposed to be sealed in Guanzhong, but he was ostracized by Xiang Yu, and he was dissatisfied with this.
At the end of the year, Liu Bang adopted Han Xin's strategy of "repairing the path of the Ming Dynasty and secretly crossing Chen Cang", and suddenly entered Guanzhong, defeated Zhang Handan, and forced Sima Xin and Dong Feng to surrender. In 205 BC, Liu Bang led a large army out of the customs, subdued the Wei king Leopard, and then occupied Hanoi County, capturing Sima Wei. However, Liu Bang did not harm Sima Wei, but led them to attack Pengcheng. In May of that year, Xiang Yu led an army to the aid of Liu Bang and launched a fierce battle with an army of 560,000 led by Liu Bang.
As a result, Liu Bang's coalition army was defeated miserably, and he himself fled in a panic, and even almost captured. In the course of the battle, these princes either ran or surrendered, such as Sima Xin the King of Sai and Dong Fei the King of Zhai, who surrendered to Xiang Yu, while Sima Wei the King of Yin died in the rebellion and was beheaded by Xiang Yu's army. Although Sima Wei died, he still had descendants who settled in Wen County, Hanoi. Sima Wei's eighth grandson, sima jun, served as a general in the Western Expedition during the Eastern Han Dynasty.
Sima Jun's son was Yuzhang Taishou Sima Liang, Sima Liang's son was Yingchuan Taishou Sima Juan, and Sima Juan's son was Jingzhao Yi Sima Fang. Sima Fang had eight sons, known as "Sima Bada", and the second of them was named Sima Yi! Although the reign of the Western And Eastern Jin Dynasties was relatively short, the Sima family still had a certain influence on Chinese history, for example, the famous historian Sima Guang was also a descendant of Sima Wei.
References: 1. "Records of History"; 2. "Book of Han"; 3. "Zizhi Tongjian"