According to "Daietsu shiki" written in the era of Trần dynasty, Nanetsukoku, a nation located in the region ranging from present Canton to North Vietnam, was the first legitimate dynasty of Vietnam, and the notion of "Tenka" which referred to this region was created.
陳朝で成立した『大越史記』においては、秦漢時代に今日の広東からヴェトナム北部に存在した南越国をヴェトナム最初の正統王朝とし、この地域を対象とする「天下」概念が形成された。