Trần Thái Tông (17 July 1218 – 5 May 1277), personal name Trần Cảnh or Trần Nhật Cảnh, temple name Thái Tông, was the first monarch of the Trần Dynasty, reigned Đại Việt for 33 years (1226–58), being Retired Emperor for 19 years. He reigned during the first Mongol invasion of Vietnam before eventually abdicating in favor of his son Trần Hoảng (Trần Thánh Tông) in 1258.