Trần Thánh Tông, the second emperor of Vietnam's Trần dynasty, took up the title of retired emperor, but continued to co-rule with his son Nhân Tông for eleven more years.

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.

The Trần dynasty, officially Đại Việt, was a Vietnamese dynasty that ruled from 1225 to 1400. The dynasty was founded when emperor Trần Thái Tông ascended to the throne after his uncle Trần Thủ Độ orchestrated the overthrow of the Lý dynasty. The Trần dynasty defeated three Mongol invasions, most notably during the decisive Battle of Bạch Đằng River in 1288. The final emperor of the dynasty was Thiếu Đế, who was forced to abdicate the throne in 1400, at the age of five years old in favor of his maternal grandfather, Hồ Quý Ly.

Trần Nhân Tông, personal name Trần Khâm, temple name Nhân Tông, was the third emperor of the Trần dynasty, reigning over Đại Việt from 1278 to 1293. After ceding the throne to his son Trần Anh Tông, Nhân Tông held the title Emperor Emeritus from 1294 to his death in 1308. During the second and third Mongol invasions of Đại Việt, the Emperor Nhân Tông and his father the Emperor Emeritus Thánh Tông were credited with the decisive victory against the Yuan dynasty and would thenceforth establish a long period of peace and prosperity over the country.