 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).