Lạc Long Quân, according to the creation myth of the Vietnamese people, was the father of the Vietnamese people. Lac Long Quan was the son and sole successor of the Khuong Loc Tuc, the King of Kinh Duong, who ruled over Xich Quy.
Lac Long Quan's wife, Au Co, gave birth to a sac containing 100 eggs from which 100 children were born. One day Lac Long Quan told Au Co: "I am descended from dragons, you from fairies. We are as incompatible as water is with fire. So we cannot continue in harmony." This said, the husband and wife parted. The man went seawards with 50 of their children, while his wife went to the mountains with the other half of the clan. The eldest son, who followed his mother, later installed himself as Vietnam's first monarch, Hung Vuong.