After the coronation of Trần Cảnh, Lý Chiêu Hoàng was demoted to Empress Chiêu Thánh (Chiêu Thánh công chúa) and his mother to Princess Thiên Cực (Thiên Cực công chúa). After the collapse of the Lý Dynasty, Trần Thủ Độ was still afraid that newly found ruling of the Trần Dynasty might be taken over by its political opponents, therefore he continued to eliminate member of Lý royal family by his ruthless method. On October 8 of Lunar calendar 1226, he forced the former emperor Lý Huệ Tông, who had already gotten rid of power to become a monk, to commit suicide and married Trần Thị Dung, Huệ Tông's former empress and his own cousin. These actions of Trần Thủ Độ was criticized by Ngô Sĩ Liên in his "Đại Việt sử kí toàn thư" as an inhumane decision despite his initial motive of reinforcing the reign of Trần Thái Tông. 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 in royal family made grand chancellor Trần Thủ Độ worried because he had profited the same circumstance of the Emperor Lý Huệ Tông to overthrow the Lý Dynasty. Therefore, in 1236 Trần Thủ Độ decided to force Trần Liễu to give up his wife Princess Thuận Thiên for the Emperor when she had been already pregnant Trần Quốc Khang for three months. After the royal marriage, Thuận Thiên was entitled the new empress of the Trần Dynasty while Chiêu Thánh was downgraded to princess.