An Dương Vương (Vietnamese: [ʔaːn zɨəŋ vɨəŋ]), personal name Thục Phán, was the founding king and the only ruler of the kingdom of Âu Lạc, an ancient state centered in the Red River Delta.

According to traditional Vietnamese histories, An Dương Vương came from the Kingdom of Shu (in modern Sichuan), which was conquered by King Huiwen of Qin in 316 BCE.

[4] In the Khâm định Việt sử Thông giám cương mục, the writers expressed doubts about An Dương Vương's origin, claiming it was impossible for a Shu prince to cross thousands of miles, through forests, and many kingdoms to invade Văn Lang.

However in the 1950s, historians Trần Văn Giáp and Đào Duy Anh argued that An Dương Vương's Shu origin was in fact true.

[5][6] In 1963, an oral tradition of Tày people in Cao Bằng titled Cẩu chủa cheng vùa "Nine Lords Vying for Kingship" was recorded.

[9][10] When King An Dương's father (Thục Chế [vi] 蜀制) died, he was still a child; yet, his intelligence enabled him to retain the throne and all the lords surrendered.

According to this legend, when the citadel was being built, all the work done was mysteriously undone by a group of spirits led by thousand-year-old white chicken seeking to avenge the son of the previous king.

It was then called "Saintly Crossbow of the Supernaturally Luminous Golden Claw" (靈光金爪神弩; SV: Linh Quang Kim Trảo Thần Nỏ); one shot could kill 300 men.

[‡ 5] However, the campaign inspired a legend whose theme is the transfer of the turtle claw-triggered crossbow from King An Duong to Zhao Tuo.

"[18] Unsuccessful on the battlefield, Zhao Tuo asked for a truce and sent his son Zhong Shi to submit to King An Dương and serve him.

[22] Zhong Shi had Mỵ Châu showed him the crossbow, at which point he secretly changed its trigger, neutralizing its special powers and rendering it useless.

The moats consist of a series of streams, including the Hoang Giang River and a network of lakes that provided Cổ Loa with protection and navigation.