Trần Thủ Độ
After a period of political crisis, the Emperor Lý Huệ Tông, himself been mentally ill for a long time, ultimately decided to cede the throne of the Lý dynasty to crown princess Lý Chiêu Hoàng in October of the lunar calendar, 1224. Ascending the throne at the age of only six, Lý Chiêu Hoàng ruled under the total influence of the commander of the royal guard, Trần Thủ Độ. Even the Empress Regnant's servants were chosen by Trần Thủ Độ; one of them was his 7-year-old nephew Trần Cảnh. When Trần Cảnh informed Trần Thủ Độ that the Empress Regnant seemed to have affection towards him, the leader of the Trần clan immediately decided to take this chance to carry out his plot to overthrow the Lý dynasty and establish a new dynasty ruled by his own clan. First Trần Thủ Độ moved the whole Trần clan to the royal palace and arranged a secret marriage between Lý Chiêu Hoàng and Trần Cảnh there, without the appearance of any mandarin or member of the Lý royal family. After that, he announced the "fait accompli" to the royal court and made Lý Chiêu Hoàng cede the throne to her new husband on the grounds that she was incapable of holding office. Thus Trần Cảnh was chosen as her successor. As a result, the 216-year reign of the Lý dynasty was ended, and the new Trần dynasty was created on the first day of the twelfth lunar month (Gregorian: December 31) 1225.