After the Spring and Autumn Period, the ancestors got their surnames.
The origin of Yuwen surname
Originated in Liaodong, then Nandan was in. During the Wei and Jin Dynasties, there was a Yuwen tribe in Xianbei in the north, claiming to be a descendant of Emperor Yan Shennong, and it was hereditary in the eastern part of Xianbei (the leader of the twelve tribes) from its ancestor Ge Wutu. After that, the general attacked Ren's adult. When he was hunting, he found a jade seal engraved with the words "Imperial Seal". He thinks he is a theocracy, so he is called Yu (the locals call heaven "Yu" and Jun "Wen", which means "emperor"). In the Eastern Jin Dynasty, when he entered the Central Plains, he was called Yu Wenguo, thought he was a surname, and was called Yu.