 During this time, there were several high-ranking officials and members of royal family of the Trần dynasty defected to Yuan's side including Thánh Tông's own brother, Prince Chiêu Quốc Trần Ích Tắc and Trần Kiện who was son of Prince Tĩnh Quốc Trần Quốc Khang.For the safeness of Thánh Tông and Nhân Tông's retreat, Princess An Tư was offered as present and diversion for prince Toghan while Marquis Bảo Nghĩa Trần Bình Trọng was captured and later killed in the Battle of Đà Mạc in defending the two emperors.In the southern border, Trần Quang Khải also had to retreat under the pressure of Sogetu's navy and the defection of the governor of Nghe An.