<P> 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 Văn Lang population . In 257 BC, a new kingdom, Âu Lạc, emerged as the union of the Âu Việt and the Lạc Việt, with Thục Phán proclaiming himself "An Dương Vương" ("King An Dương"). Some modern Vietnamese believe that Thục Phán came upon the Âu Việt territory (modern - day northernmost Vietnam, western Guangdong, and southern Guangxi province, with its capital in what is today Cao Bằng Province). </P> <P> After assembling an army, he defeated and overthrew the eighteenth dynasty of Hùng kings, around 258 BC . He proclaimed himself An Dương Vương ("King An Dương"). He then renamed his newly acquired state from Văn Lang to Âu Lạc and established the new capital at Phong Khê in the present - day Phú Thọ town in northern Vietnam, where he tried to build the Cổ Loa Citadel (Cổ Loa Thành), the spiral fortress approximately ten miles north of that new capital . However, records showed that espionage resulted in the downfall of 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 . </P> <P> In 207 BC, Qin warlord Triệu Đà (pinyin: Zhao Tuo) established his own independent kingdom in present - day Guangdong / Guangxi area . He proclaimed his new kingdom as Nam Việt (pinyin: Nanyue), starting the Triệu dynasty . Triệu Đà later appointed himself a commandant of central Guangdong, closing the borders and conquering neighboring districts and titled himself "King of Nam Viet" In 179 BC, he defeated King An Dương Vương and annexed Âu Lạc . </P> <P> This period is controversial as on one side, some Vietnamese historians consider Triệu's rule as the starting point of the Chinese domination, since Triệu Đà was a former Qin general, whereas others consider it still an era of Vietnamese independence as the Triệu family in Nam Việt were assimilated to local culture . They ruled independently of what then constituted the Han Empire . At one point, Triệu Đà even declared himself Emperor, equal to the Han Emperor in the north . </P>

Who established the nam viet kingdom in the third century bce