An Duong Vuong (安陽王) is the title of Thục Phán (蜀泮), who ruled over the ancient kingdom of Âu Lạc from 257 to 207 BCE, after defeating the state of Văn Lang and uniting the two tribes Âu Việt and Lạc Việt. His longevity, said to have been approximately 100 years, is quite debatable.

Historical accounts

According to old historical records Đại Việt sử ký toàn thư and Khâm Định Việt Sử Thông Giám Cương Mục, Thục Phán was a prince of the Chinese state of Shu (蜀, which shares the same Chinese character as his surname Thục), sent by his father first to explore what are now the southern Chinese provinces of Guangxi and Yunnan and second to move their people to modern day northern Vietnam during the invasion of the Qin Dynasty.

However, modern Vietnamese scholars claim that "Thục Phán" was a native Austro-Asiatic name which meant "God of crossbow", and that he was an indigenous Vietnamese.

Thục Phán apparently came upon the Âu Việt (甌越) territory (modern-day northernmost Vietnam, western Guangdong, and southern Guangxi province, with its capital in what is today Cao Bang Province). After assembling an army, he defeated King Hùng Vương (雄王) XVIII, the last ruler of the Hồng Bàng Dynasty, around 257 BCE. He proclaimed himself An Dương Vương (安陽王, "King An Dương"). He then renamed his newly acquired state from Văn Lang to Âu Lạc (甌雒/甌駱) and established the new capital at Phong Khê in the present-day Phú Thọ town in northern Vietnam, where he tried to build Cổ Loa Thành (Co Loa Citadel), the spiral fortress approximately ten miles north of that new capital.

Thục Phán and Âu Lạc’s Administration

There is not much recorded or written about how the new Âu Lạc was administered and organized. Nonetheless, based on Thục Phán's accomplishments, he is assumed to have been an astute, intelligent, and significant figure. Certainly he was a talented general who knew how to exploit the confusion and turmoil in China during that period, not only to grab a piece of land for himself but also to secure his state's prosperity and survival. Around that same time, various states were fighting for control of China. Eventually, the Qin state rose to power and unified China under Emperor Qin Shi Huang. While Qin Shi Huang ordered the construction of the Great Wall, An Dương Vương had begun the construction of a spiral fortress called Cổ Loa Thành to defend against invasions.

The Legend of Cổ Loa Thành and the Magic Crossbow

Cổ Loa Thành and Âu Lạc

After Thục Phán defeated the last Hùng Vương King and ascended to the throne as An Dương Vương, he renamed Văn Lang to Âu Lạc and established Co Loa Citadel (古螺) as the new capital. He saw the strategic and geographic importance of Cổ Loa. On two of its sides, Co Loa was surrounded by impenetrable mountains and forests. There was also a river flowing by. No one knows why An Dương Vương favored the spiral, shell-like shape of Cổ Loa Thành, but legend has it that its construction was extremely tough and difficult to complete. Each time it seemed near completion, it was undone at night by a hoard of evil spirits.

The Legend of Cổ Loa and the Magic Crossbow

An Dương Vương burnt incense, prayed, made offerings, and evoked the gods to help him. One night, in a dream, a very, very old and venerable man with long, white hair came to him and told him the only person who could help him build his citadel was a golden turtle that lived somewhere around Cổ Loa.

A few days later, while sitting in a boat on the river and thinking about the meaning of his dream, a giant golden turtle appeared suddenly out of the water. The golden turtle told An Dương Vương that he would need one of its claws in order to accomplish his plan. Pulling out one of its claws and throwing it to An Dương Vương, the turtle vanished.

An Dương Vương had Cao Lỗ, his weaponry engineer, build a crossbow incorporating this claw which could shoot thousands of arrows at once. Indeed right after obtaining this claw, An Dương Vương saw his fortunes change. His capital started taking shape. His kingdom prospered and soon was coveted by neighboring states. Among one of those who coveted his territory was Zhao Tuo (Triệu Đà in Vietnamese), a Qin general who refused to surrender to the newly established Han Dynasty. For a period of ten years around 217 to 207 BCE, Triệu Đà attempted many invasions to conquer Âu Lạc but failed each time due to An Dương Vương's military skills and defense tactics.

Triệu Đà's Scheme

Triệu Đà (趙佗), having been beaten several times, devised a new plan. He negotiated a peace treaty with Âu Lạc (甌雒/甌駱). He determined to find out where lay the strength and strategies of his foe. He even went so far as to propose marriage between An Dương Vương’s daughter, Princess Mỵ Châu (媚珠) and his son Trọng Thủy (仲始). In time Triệu Đà found out through his daughter-in-law Mỵ Châu that An Dương Vương had a magic crossbow that made him almost invincible. Triệu Đà then he told his son Trọng Thủy to sneak into his father-in-law's palace and steal this "magic crossbow", replacing it with a fake. Triệu Đà, with the magic crossbow in his hands, launched a new attack on his foe and in-law An Dương Vương.

The loss of Cổ Loa and the Magic Crossbow

This time, Cổ Loa fortress fell into Triệu Đà's hands. An Dương Vương grabbed Mỵ Châu, his only daughter, and fled the scene of the battle. He rode to the river and encountered the giant golden turtle, which told An Dương Vương, “The person responsible for this defeat is sitting right behind you!”

Angered by his own daughter's betrayal, the king slew his daughter (in a popular version of the tale he beheaded her). Then he jumped into the river with the giant golden turtle.

Trọng Thủy, searching for his beloved wife, arrived a few minutes later at the scene. The body of his beloved wife was lying in a pool of blood and his father-in-law was nowhere to be seen. In accordance with conjugal fidelity and devotion, he drew his sword and killed himself as well, in order to be with his wife forever in eternity.

Having defeated An Duong Vuong, Triệu Đà annexed the newly conquered territory to his own and created the Nan Yue state, proclaimed himself a new emperor of the Triệu Dynasty (207-111 BCE).