History of Vietnam - Wikipedia, the free encyclopedia
By the 3rd century BC, another Viet group, the Âu Việt, emigrated from present-day southern China to the Red River delta and mixed with
the indigenous Van Lang population. In 258 BC, a new kingdom, Âu Lạc, emerged as the union of the Âu Việt and the Lạc Việt, with Thục Phán proclaiming himself "King An Dương Vương". At his capital Cổ Loa, he built many concentric walls around the city for defensive purposes. These walls, together with skilled Âu Lạc archers, kept the capital safe from invaders for a while. However, it also gave rise to the first recorded case of espionage in Vietnamese history, resulting in the downfall of king An Dương Vương.
In 207 BC, an ambitious Chinese warlord named Triệu Đà (Chinese: Zhao Tuo) defeated king An Dương Vương by having his son Trọng Thủy (Chinese: Zhong Shi) act as a spy after marrying An Dương Vương's daughter. Triệu Đà annexed Âu Lạc into his domain located in present-day Guangdong, southern China, then proclaimed himself king of a new independent kingdom, Nam Việt (Chinese: 南越, Nan Yue). Trọng Thủy, the supposed crown prince, drowned himself in Cổ Loa out of remorse for the death of his wife in the war.
Some Vietnamese consider Triệu's rule a period of Chinese domination, since Triệu Đà was a former Qin general. Others consider it an era of Việt independence as the Triệu family in Nam Việt were assimilated to local culture. They ruled independently of what then constituted China's (Han Dynasty). At one point, Triệu Đà even declared himself Emperor, equal to the Chinese Han Emperor in the north.