To the Vietnamese people, Hung Vuong are considered the founders of their nation, the forefather who had built the basic foundation of the Vietnamese society in the old time. This legend was transmitted orally from generations to generations and has been becoming very familiar to every Vietnamese. It was to appear on the first page of every work of historians in the past, usually commissioned by the ruling dynasties, such as: Dai Viet Su Ky Toan Thu (Complete History of Dai Viet) edited by historians of the Nguyen Dynasty; Kham Dinh Viet su Thong giam Cuong muc (Summary of the Vietnamese History established by imperial order) edited by historian Ngo Si Lien and collaborators under the Lê Dynasty. The legend was harshly discussed by different scholars who based their criticism on the lack of documents and the chronology of the facts involved in the legend. But it is so attached to the memory of the Vietnamese people to become their common heritage that reveals an origin and a reason to keep them closely united.
According to the legend, the third descendant of King Than Nong, named De Minh, on his travel to control the southern pant of his kingdom, arrived at the region of Ngu Lïnh, met and married Vu Tien. They had a son named Loc Tuc. Loc Tuc was very intelligent and virtuous, and his father wanted to cede him the throne. But he refused the offer and persuaded his father to pass it on to his elder brother, prince De Nghi. So, De Minh made his eldest son De Nghi his heirs but also conferred Loc Tuc king of the South with the title Kinh Duong Vuong, and the name of the country as Xich Quy.
Kinh Duong Vuong married Long Nu, the daughter of Dong Dinh Vuong - sovereign of the Dong Dinh lake - and gave birth to Sung Lam. When he succeeded his father Sung Lam took the title as Lac Long Quan. Lac Long Quan married au Co the daughter of De Lai and grand child of De Nghi. au Co gave birth to a bag containing one hundred eggs hatching out to one hundred sons. Sometimes later, Lac Long Quan said to au Co: "I am the son of a Dragon, and you are a fairy. We are different in nature and cannot extend our living together. It is time for us to be departed. I'll take fifty of our sons to my kingdom on the sea; the other fifty sons will follow you to the uplands to establish another sovereignty."
Au Co and her fifty sons went to the highlands. She crowned the eldest son, King Hung. Hung Vuong named the country Van Lang and made Phong Chau its capital. So, began the dynasty of Hong Bang, and with it the foundation of the Vietnamese nation.
Hung Vuong divided the country into fifteen counties, called his civilian officials Lac Hau and his military officers Lac Tuong. He also titled his sons as Quan Lang and his daughters My Nuong. The dynasty of Hong Bang lasted for eighteen generations, all of its kings taking the same title Hung Vuong.