Thousands of years ago, Kinh Duong Vuong reigns over the Xich Quy kingdom that spread in the North up to the Blue river; in the South to Central Vietnam; in the West up to Sseutchouan; and in the East as far as the sea. Kinh Duong Vuong married Long Nu, a princess from Dong Dinh Ho. Because of Long Nu's origin, their son Sung-Lam, popularly known as Lac Long Quan, was believed to be descended from the line of the Dragons. He succeeded to the throne of his father, and governed the Lac Viet tribe. Lac Long Quan had superhuman strength. He liked to stay near the water, so he resided along the seashore. Lac Long Quan protected Lac Viet people from being harmed by devils and monsters. He helped them fight against nature disasters. He taught them how to crop and to sew. He also taught them to cook rice in the bamboo tube. At that time, De-Lai is a King of another northern tribe made a trip to the South. De-Lai has a daughter named Au Co. She is very beautiful. One day, Lac Long Quan wondered on the mountain area. He met Au Co and fell in love with her. He built her a castle on a rocky mountain. Lac Long Quan then married Au Co and lived with her. Au Co gave birth to a big sac. Inside there were one hundred eggs. Each egg in turn hatched into one little boy. These boys grew up very fast, became brave strong men. Even though Lac Long Quan had a big family, he still missed his old living near the Coast. One day, he said to Au Co: - I am from the Dragon line. I like to dwell in the Coast. You are from the Fairy line, you like to be on highlands. Therefore we cannot live together. It is better that we separate now. You shall take fifty children to the highlands and I shall take fifty children to the Coast. The children then spread out, divided and ruled the lands. They were ancestors of Lac Viet.