The Âu Việt or Ouyue (Chinese: 甌越) were an ancient conglomeration of Baiyue tribes living in what is today the mountainous regions of northernmost Vietnam, western Guangdong, and northern Guangxi, China, since at least the third century BCE.
The Western Ou (西甌; pinyin: Xī Ōu; Tây meaning "western") were other Baiyue tribes, with short hair and tattoos, who blackened their teeth[1] and are the ancestors of the modern upland Tai-speaking minority groups in Vietnam such as the Nùng and Tay,[2][3] as well as the closely related Zhuang people of Guangxi.
He named the new nation "Âu Lạc", proclaiming himself "An Dương Vương" (literally "Peaceful Virile King").
There may be some merit to the story due to archaeological evidence of cultural ties between Yunnan and the Proto-Vietnamese, but possibly as a result of the gap in time between the origin of the story and when it was recorded, the location could have been changed to Shu or simply mistaken due to erroneous geographical knowledge.
[4] According to a translated oral account of a Tày legend, the western part of Âu Việt's land became the Nam Cương Kingdom,[5] whose capital was located in what is today the Cao Bằng Province of Northeast Vietnam.