Trần Thủ Độ
Trần Quốc Khang was born in 1237 as the first son of the Emperor Trần Thái Tông and his new empress Thuận Thiên. According to "Đại Việt sử kí toàn thư", Thái Tông and his wife, the Empress Chiêu Thánh, did not have their first son for a while. This situation made grand chancellor Trần Thủ Độ worried, because he had profited from the same circumstance with the Emperor Lý Huệ Tông to overthrow the Lý Dynasty and create the Trần Dynasty. Therefore, Trần Thủ Độ decided to force Thái Tông's elder brother, Prince Hoài Trần Liễu, to give up his wife Princess Thuận Thiên for the Emperor when she had been already pregnant with Trần Quốc Khang for three months. After the royal marriage, Thuận Thiên was styled the new empress of the Trần Dynasty, while Chiêu Thánh was downgraded to princess. In the fury of losing his pregnant wife, Trần Liễu rose a revolt against the royal family, and Thái Tông felt awkward about the situation and decided to become a monk in Yên Tử Mountain. The stable state was only restored when Trần Thủ Độ successfully persuaded Thái Tông to return to the throne and put down Trần Liễu's revolt. Vietnamese historians in the feudal era, such as Ngô Sĩ Liên or Phan Phu Tiên, often criticized decisions of Trần Thủ Độ and Trần Thái Tông in this event and considered it as the root cause for the downfall of the Trần Dynasty afterwards, during the reign of Trần Dụ Tông.