When Shennong was the leader of an ancient tribe, there was a minister who specialized in divination named Si Guai, and his descendants took Si as their surname and called him Si Shi. In the Spring and Autumn Period, Zheng had a doctor named Si Cheng, and his grandson took Zuzi as his surname. It's a branch of the company. After careful study, the descendants of the surname Si became the ancestor of the surname Si. In the Spring and Autumn Period, there was a doctor's uncle tiger in the State of Jin, who was sealed in the state of Miao and established the state of Miao, and there was a noble scholar and minister, and later he was also named Si. In the Spring and Autumn Period, there was Cheng Guo, an earl, who was called Cheng Bo. By the time Cheng Bo divorced his father, he was a Sima official of the Zhou royal family, and was given the title of official family, so his descendants took the surname of Si. During the Spring and Autumn Period, there was a son Ying in Wei Linggong, the country of Wei, whose descendants were Wei Sikou, and the descendants took the official as their surname, and later changed to the single surname Si. In history, the descendants of the compound surnames Si De and Si Cheng were also changed to the single surname Si, which was called Si Shi.
Sima
The first origin: it originated from the official position, and came from Cheng Bo, the minister in charge of military power in the Western Zhou Dynasty, who took the official position as his surname. In ancient times, some people valued Li, who was the official in charge of heaven and earth. Tang Yao once cared for Li. During Zhou Xuanwang's period, Cheng Bo divorced his father, and he was the official to Sima, in charge of the national army, assisting the government and assisting the country, with great power. Later, Cheng Boxiu's father, Keping Xu Fang, made great contributions. Zhou Xuanwang allowed him to take his official position as his surname, and later he became Sima. The second origin: from the birth surname, from Si Marui, Emperor of Jin Dynasty and Yuan Dynasty, who changed his surname to surname for some reason, or changed his surname to surname by official title. This branch of Sima's family came from Si Marui, Emperor of the Jin Dynasty. It was originally named Niu, but later changed its surname to Sima because of its position. Its descendants also became Sima's family, which has been passed down from generation to generation. [This is a legend] The third origin: from the change of surname, from the change of surname Xu Shi of Ji and the change of surname Hao, belonging to the change of surname to surname for some reason. Xu Mu and Hao Yun, some of their descendants changed to Sima for some reason. The ancestor of the surname: Cheng Bo divorced his father. According to the historical records "A Brief History of the Clan", the ancestor of Sima's surname was Cheng Bo's father who worshipped Sima (the official position in charge of military and political affairs and campaigns) during Zhou Xuanwang's administration. Because of his repeated active campaigns, he was given the surname Sima, and his descendants took Sima as their surname. Cheng Bo's father, a vassal in the Yin and Zhou Dynasties, was handed down by the descendants of Zhu Rong's family after Emperor Zhuan Xu in ancient times. Some of the descendants of Cheng Bo's divorced father took the official as their surname and took the surname Sima. Some of them took the surname Cheng according to the convention of "taking the country as their surname". Therefore, the Sima family is the Cheng family, and the Cheng family is a family. Sima's surname was about 27 years ago. The descendants of Sima family regarded Cheng Bo's father as the ancestor of Sima family.