This paper re-examines the historiography of Đại Việt during the Trần Dynasty, which developed in close connection with contemporary myths and legends - most notably the Lĩnh Nam chích quái. Although the relationship among dynastic chronicles such as Lê Văn Hưu’s Đại Việt sử ký (1272), Lê Dynasty’s Đại Việt sử ký toàn thư (1479), and (Đại) Việt sử lược compiled during the Trần period have long been a subject of scholarly interest. The discovery of the Beijing Normal University manuscript of Đại Việt sử lược, which, despite being a Qing Dynasty handwriting copy, reflects the naming taboos (kiêng húy) of early Trần royal family members, offers a fresh perspective on the debate. In this paper, the author demonstrates that by comparing the narratives in the Đại Việt sử lược regarding the national foundation, the decline of the Lý Dynasty, and the establishment of the Trần Dynasty with other historical sources, it is highly probable that the Đại Việt sử lược (as well as Lê Văn Hưu’s Đại Việt sử ký) reflects the political climate spanning from the resistance against the Mongols to the 1330s. In contrast, the foundation myths and the portrayal of Trần authority found in works such as Lĩnh Nam chích quái or Đại Việt sử ký toàn thư reflect a later period. This was an era led by Confucian scholar-officials attempting to navigate the “14th-century Crisis” and implement national institutional reforms that fundamentally reshaped Vietnamese history.