[2] In 1292 he was invested as crown prince by Nhân Tông[3] and ultimately was ceded the throne in 1293 while his father still reigned as Retired Emperor (Thái thượng hoàng) for 16 years.

According to officially commissioned historical books, although being an intelligent ruler and a devoted son,[4] the young Emperor Anh Tông often drank alcohol and escaped from the royal citadel to wander around Thăng Long at night.

[2][4] Foreign policy during Anh Tông's reign was continuing the détente with the Yuan dynasty while restraining the two other neighbours of Đại Việt, the kingdoms of Champa and Laos.

[8] After the failed invasions of the Mongol Empire, Đại Việt's southwestern border was invaded several times by Laos until Anh Tông appointed Phạm Ngũ Lão to oversee the pacification of the frontier regions.

[9][10][11] In 1306, the king of Champa Chế Mân offered Vietnam two Cham prefectures Ô and Lý in exchange for a marriage with Vietnamese princess Huyền Trân.

He was known as a modest ruler who was quick to mend his mistakes, was always cautious and intelligent in judgment, and the only major criticism of him was building a tower and gathering monks in Yên Tử mountain.