Trần Thánh Tông, emperor of Vietnam (then Đại Việt) (died 1290)

Trần Thánh Tông, personal name Trần Hoảng (陳晃), was the second emperor of the Trần dynasty, reigning over Đại Việt from 1258 to 1278. After ceding the throne to his son Trần Nhân Tông, Thánh Tông held the title of retired emperor from 1279 until his death in 1290. During the second and the third Mongol invasions of Đại Việt, Retired Emperor Thánh Tông and Emperor Nhân Tông were credited as the supreme commanders who led the nation to the final victories and, as a result, established a long period of peace and prosperity over the country. With his successful rulings in both military and civil matters, Trần Thánh Tông was considered one of the greatest emperors of not only the Trần dynasty but also the whole dynastic era in the history of Vietnam.

Đại Việt, was a Vietnamese monarchy in eastern Mainland Southeast Asia from the 10th century AD to the early 19th century, centered around the region of present-day Hanoi. Its early name, Đại Cồ Việt, was established in 968 by the ruler Đinh Bộ Lĩnh after he ended the Anarchy of the 12 Warlords, until the beginning of the reign of Lý Thánh Tông, the third emperor of the Lý dynasty. Đại Việt lasted until the reign of Gia Long, the first emperor of the Nguyễn dynasty, when the name was changed to Việt Nam in 1804. Under rule of bilateral diplomacy with Imperial China, it was known as Principality of Giao Chỉ (975–1164) and Kingdom of Annam (1164–1804) when Emperor Xiaozong of Song upgraded Đại Việt's status from principality to kingdom.