Au Co

Âu Cơ
Au Co is shown on the left, while her husband Lạc Long Quân is in the center. This display was created for the 2009 Tet festival.

Âu Cơ () was, according to the creation myth of the Vietnamese people, an immortal mountain fairy who married Lạc Long Quân (literally: "Dragon Lord of Lac"), and bore an egg sac that hatched a hundred children known collectively as Bach Viet, ancestors to the Vietnamese people. Âu Cơ is often honored as the mother of Vietnamese civilization.

Âu Cơ was a young, beautiful fairy who lived high in the mountains. She traveled to heal those who suffered because she was skillful in medicine and had a sympathetic heart. One day, a monster frightened her, so she turned into a crane to fly away. Lạc Long Quân, a dragon king from the sea, saw her in danger, so he grabbed a rock and killed the monster. When Au Co stopped to see who helped her, she turned back into a fairy and fell instantly in love with her benefactor. She bore an egg sac from which hatched 100 children. However, despite their love, she desired to be in the mountains again and he yearned for the sea. They separated, each taking 50 children. Au Co settled in mountainous northern Vietnam where she raised 50 young, intelligent, strong leaders, later known as the Hùng Vương, Hùng kings.

The books Đại Việt sử ký toàn thư (from the 15th century) and Lĩnh Nam chích quái (Wonders plucked from the dust of Linh-nam, from the 14th century) mention the legend. In Đại Việt sử ký toàn thư Âu Cơ is the daughter of Đế Lai (also known as Đế Ai 帝哀, or Emperor Ai, who was a descendant of Shennong), while in Lĩnh Nam chích quái she is the wife of Đế Lai. The story of Âu Cơ and Lạc Long Quân is taught widely in Vietnamese schools.