abstract:Li Cong (李琮) (died 752), né Li Sizhi (李嗣直), known as Li Tan (李潭) from 725 to 736, posthumously honored Crown Prince Jingde (靖德太子) and then Emperor Fengtian (奉天皇帝, literally, "the emperor who submitted to Heaven"), was an imperial prince of the Chinese dynasty Tang Dynasty. He was the oldest son of Emperor Xuanzong but, despite that status, was never made crown prince, bypassed in favor of his younger brothers Li Ying and Li Heng (the later Emperor Suzong).