 In October 1282, the Retired Emperor Trần Thánh Tông and the Emperor Trần Nhân Tông gathered all members of royal family, Trần clan and officials in royal court in Bình Than to discuss about the unadvoidable war.Two prominent generals of the Đại Việt army who were noticed on this occasion were Trần Khánh Dư, former commander of the army but was deprived of all titles after his guilt, and Trần Quốc Toản, a marquis who was only sixteen years old.In 1283, Prince Hưng Đạo Trần Quốc Tuấn was appointed as commander in chief (Quốc công tiết chế) of Đại Việt army, the Retired Emperor and the Emperor began to hold military exercises with their generals and troops.