The origins of the Yu surname are:
1. From the surname Ji
He is a descendant of Ji Fa, King Wu of Zhou Dynasty, and takes the name of the country. According to the "New Tang Book: Genealogy List of Prime Ministers", in the early years of the Western Zhou Dynasty, after King Wu of Zhou conquered Shang, he enfeoffed the princes on a large scale. His second son, Uncle Xie, was granted the title of Xie State. Later, Uncle Xie's descendants took the country's surname as their surname. Some took the surname Xie, while others took the surname next to the city and named it Yu. They became the Henan Yu surname.
2. It comes from the Chunyu family, a descendant of the ancient Yan Emperor Jiang, a son of Qi State and a descendant of the writer Chunyu Kun.
In the Tang Dynasty, it was taboo that Xianzong Li Chun changed his surname to Yu. According to "Dialectics of Ancient and Modern Surname Books", the descendants of Chunyu Gong took the country's name as their surname and were called the Chunyu family. Among the seven royal surnames designated during the Zhenguan period of the Tang Dynasty, Chunyu was the surname. By the time of Li Chun, Emperor Xianzong of the Tang Dynasty, the compound surname Chunyu was changed to the single surname Yu to avoid taboos ("Chun" and "Chun" are the same pronunciation).
3. It comes from the Yu family in the Central Plains in the early Northern Wei Dynasty, who changed his surname in Pingcheng to avoid the chaos of the Three Kingdoms.
During Emperor Xiaowen's sinicization reform, his original surname was restored to Yu. According to "History of the Road", the Wanfeng Yu clan of the Xianbei tribe was originally from Shandong Province, but was later changed with the Xianbei customs, and was restored to the surname after Emperor Xiaowen's sinicization reform. In fact, they are the descendants of Yu Gong of the Han Dynasty. During the war of the Three Kingdoms, they left the Central Plains with the Tuoba tribe and changed their surname to Wanbo Yu in order to adapt to the Xianbei people.
The migration and spread of the Yu surname:
The earliest reproduction and spread of the Yu surname was in the northern area of ??Qinyang in present-day Jiaozuo. This is the seat of the ancient Ming Kingdom and the birthplace of the Yu surname. . After the fall of the Wei Kingdom, the people of the Yu surname mainly lived in present-day Henan Province, and their migrations were mainly in Henan, such as Fangcheng, Wutang, Xuchang, Funiu Mountain and other places.
During the Qin and Han Dynasties, people with the surname Yu began to slowly migrate to the surrounding areas with Henan as the center. Those who moved north went to Shanxi and Hebei, those who moved east to Anhui and Shandong, and those who moved west. Shaanxi and Gansu. During this period, the Yu surname mainly took the Central Plains region as the center of reproduction and migration, and formed three major counties, namely Henan, Donghai, and Hanoi. Among them, those with the Yu surname who moved eastward to Shandong were the most prosperous.
During the Wei, Jin, Southern and Northern Dynasties, the surname Yu really became popular throughout the country. Due to the long-term disputes between warlords, many people of the Yu surname followed the fleeing army and moved south to the vast area in the southeast. During the "Five Chariots in China", exchanges and integration among ethnic groups were promoted.
Reference for the above content: Baidu Encyclopedia—Yu Surname