李昭皇
In October 1224, Lý Huệ Tông decided to cede the throne to his daughter, the Princess Chiêu Thánh, now the Empress Regnant Lý Chiêu Hoàng. Chiêu Hoàng was only six at that time so every important decision in the royal court was made by the Trần clan. Profiting from this circumstance, Trần Thủ Độ arranged a marriage between Chiêu Hoàng and Trần Cảnh, the eight-year-old son of Trần Thừa. With Trần Cảnh being the Empress Regnant's husband, Trần Thủ Độ was finally able to overthrow the Lý Dynasty by making Lý Chiêu Hoàng pass the throne to Trần Cảnh, now Trần Thái Tông, in 1225. After the coronation of his son, Trần Thừa acted as Regent of the Emperor but it was Trần Thủ Độ who decided both military and civil activities in royal court. In October 1226, Trần Thừa was honoured by the title Retired Emperor as Trần Thái Tổ, the first retired emperor of the Trần Dynasty.