李惠宗
By the 1190s, more outsider clans were able to penetrate and infiltrate the royal family, weakening further the Ly authority. Three powerful aristocratic families–Doan, Nguyen, and Tran (descendants of Tran Kinh, a Chinese emigre from Fujian) emerged in the court and contested on behalf of the royals. In 1210, Cao Tong’s eldest son Lý Sảm became king Lý Huệ Tông (r. 1210–1224) of Dai Viet. In 1224, Lý Sảm appointed his second princess Lý Phật Kim as successor while he abdicated and became a monk. Finally, in 1225 the Tran leader Tran Thu Do sponsored a marriage between his eight-year-old nephew Trần Nhật Cảnh with Queen Phật Kim, that means the Ly would give up power to the Tran, and Trần Nhật Cảnh became king Trần Thái Tông of the new dynasty of Dai Viet.