The Lạc Việt or Luoyue were an ancient conglomeration of Yue tribes that inhabited what is todayGuangxi in Southern China and the lowland plains of Northern Vietnam, particularly the marshy, agriculturally rich areas of the Red River Delta. They are the owners of Bronze AgeĐông Sơn culture in mainland Southeast Asia and direct ancestors of Vietnamese people. In Vietnamese mythology, the Lạc, a giant, crane-like bird appeared to the ancient tribes in southern China and guided them through a difficult journey to northern Vietnam. This mysterious bird was later depicted on the elaborate bronze drums from the northern Vietnamese Đông Sơn culture that flourished during the Bronze Age. The Lạc people's ancestors called themselves the Lạc Việt after the bird in its honor. The ethnonym Lạcs etymology is uncertain. Based on Chinese observers' remarks that the Lạc people's paddies depended on water-control systems like tidal-irrigation & draining, so that the floody, swampy Red River delta might be suitable for agriculture, many scholars opted to find its etymology in the semantic field "water". Japanese scholar Gotō Kimpei links Lạc to Vietnamese noun lạch~rạch "ditch, canal, waterway". Vietnamese scholar Vũ Thế Ngọc cites Nguyễn Kim Thản's opinion that Lạc simply means "water" and is comparable to phonetically similar elements in two compounds nước rạc & cạn 'rặc ; indeed, Hồ Ngọc Đức's Free Vietnamese Dictionary Project glosses rặc as "means tidal water when falling". Meanwhile, Vũ himself compares Lạc to the common Vietnamese noun nước "water" as well as its Austroasiatic cognates like Stiengđaák, Sedangđák, Churuđạ, Kơhođa, etc.. According to legend, the Lạc Việt founded a state called Văn Lang in 2879 BC. The people of Văn Lang supposedly traded with the upland-based Âu Việt people, who lived in the mountainous regions of what are today northernmost Vietnam, western Guangdong, and northern Guangxi, China, to their north, until 258 BC or 257 BC, when Thục Phán, the leader of the alliance of Âu Việt tribes, invaded Văn Lang and defeated the last Hùng king. He united the two kingdoms, naming the new nation Âu Lạc and taking a Sino-Vietnamese title, "peaceful virile king".
