 Complete the following phrase:  Trần Thánh Tông October 12, 1240  July 3, 1290, personal name Trần Hoảng , 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 to his death in 1290. During the second and the third 