李昭皇
Emperor Huệ Tông did not have a son as heir. Captain Trần Thủ Độ (Trần Thừa's cousin) then decided the emperor's second daughter Princess Chiêu Thánh will be crowned as Queen of Đại Việt. In 1224, Huệ Tông abdicated and gave the throne to the crowned princess. Lý Chiêu Hoàng, at 6 years old, became the first reigning queen of Vietnam.