 During the second and the third Mongol invasions of Đại Việt, the Retired Emperor Thánh Tông and the 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 ruling in both military and civil matters, Trần Thánh Tông was considered as one of the greatest emperors of not only the Trần dynasty but also the whole dynastic era in the History of Vietnam.Thánh Tông was born on September 25 of the lunar calendar 1240 as Trần Hoảng, the second prince but the first natural son of the Emperor Trần Thái Tông and Empress Consort Thuận Thiên.