Unlike his famous brothers Trần Quang Khải or Trần Nhật Duật, Prince Tĩnh Quốc (Vietnamese: Tĩnh Quốc vương) Trần Quốc Khang was not an important figure in the royal court during Đại Việt's war of resistance against the Mongol invasion. While Trần Quang Khải was appointed by the Emperor Trần Thánh Tông as minister at age 20, Trần Quốc Khang was not considered capable for an important position and thus he held only some nominal high-ranking title, but without real power in the royal court. However, Prince Tĩnh Quốc always lived in good term with his brothers. It was said that one time when the Retired Emperor Thái Tông wore a white cotton coat, Trần Quốc Khang tried to make the Retired Emperor award him this coat by a dance and finally achieved his purpose, but when the Emperor also wanted to get the coat by another dance, Prince Tĩnh Quốc said: "Even for the most precious thing, the throne, Your Majesty's humble subject [Quốc Khang] did not want to fight with the second brother [Thánh Tông]. Now the Retired Emperor awards me this negligible coat and the second brother still wants to deprive me of it?" His answer was praised by Thái Tông: "So you think that the throne has the same value as this mediocre coat."