Zeng's family originated from Si's family.
The 25th son of the Yellow Emperor, named Changyi, was born in Zhuan Xu, Zhuan Xu was born in Gun, and Gun was born in Yu. According to legend, Yu was born to Gun's wife, dream of eating, who gave Yu a surname. The Zeng tribe who invented Zan is a branch of Zan tribe. Yu succeeded in harnessing water, and Shun abdicated to Yu. Yu's son Qi established the Xia Dynasty, the first hereditary dynasty in the history of China.
The capital of the Xia Dynasty was established in Yangcheng, which is now the southeast of Dengfeng County, Henan Province. Shao Kang, Wang Xia, made Qu Lie, the second son, viscount Kun, and established a state in Kun (now Xiangcheng Town, Lanling County, Linyi City, Shandong Province). In ancient times, there was a custom of taking fiefs as surnames, so Qu Lie took Zhi as surnames from now on. The weak mountain country went through Xia, Shang and Zhou Dynasties, and it was not until the Spring and Autumn Period, that is, 567 BC, that it was destroyed by the State of Ju. With the pain of national subjugation, the king of Wu came out and ran to neighboring Lu. Later, the original country name "Tan" was changed to the surname, and the name "Zeng" was removed, which meant leaving the old city and not forgetting the ancestors.
Source 2:
In the past, all ethnic minorities had surnames. There are a few Zeng surnames among Jing, Yi, Tujia, Buyi, Manchu, Miao and Li, but most of them are Han.
Zeng surname is a traditional Han surname, which originated in the northwest of Lanling County (Cangshan County) in Linyi City, Shandong Province. Wang Xia Shao Kang gave his youngest son Qu Lie a fief as the kingdom of the viscount, which is called Guo Zi. After the extinction of Zhi State, the King Zhi Wu went to neighboring Shandong and took the original country name Zhi as his surname, but removed Yi to show that he did not forget his ancestors when he left his old city, so he called it Zeng.
Zeng has the saying that "there was no such thing as two in the world". This means that Zeng's family name has not been taken as a surname by foreigners or people with foreign surnames for a long time. Today's Zeng people are descendants of Wu Wang, a descendant of Yu 4000 years ago.
At present, China has a population of more than 7.7 million, ranking 3 1. Hunan is Zeng's largest province. Sichuan is the third largest province with Zeng surname, with about 300,000 people, ranking more than 50 among the surname population in the province.