All that was recorded in history about his origins was that his father Feng Zhang—given variously as 馮璋[4] or 馮章[5]—was the doorkeeper for Li Siyuan, the future Later Tang emperor.
[6] Sometime after Li Siyuan took the throne, he made Feng Yun a protocol officer (中門使, Zhongmenshi) and director of palace affairs (宣徽使, Xuanhuishi).
He later served as the military governor of Zhongwu Circuit (忠武, headquartered in modern Xuchang, Henan).
In 933, Li Siyuan was prepared to make him a chancellor—usually, with the designation Tong Zhongshu Menxia Pingzhangshi (同中書門下平章事)—but as this would violate naming taboo for Feng (as his father was named Feng Zhang), Li Siyuan gave him the unusual designation Tong Zhongshu Menxia Erpin (同中書門下二品) as chancellor, and also made him full director of the three financial agencies.
Despite Li Siyuan's displeasure (as he felt that they were abandoning him in his illness), he first allowed Zhao to leave to become the military governor of Xuanwu Circuit (宣武, headquartered in modern Kaifeng, Henan), replacing him with Zhu Hongzhao; and later also allowed Fan to leave to serve as the military governor of Chengde Circuit (成德, headquartered in modern Shijiazhuang, Hebei), replacing him with Feng.
[5] As Zhu Hongzhao believed himself to be the person most instrumental to Li Conghou's enthronement, he tried to dominate the court scene.
He and Feng Yun similarly distrusted the imperial guard generals An Yanwei (安彥威) and Zhang Congbin (張從賓), and An and Zhang were sent out to be the military governors of Huguo and Zhangyi (彰義, headquartered in modern Pingliang, Gansu), respectively, and replaced with Zhu Hongshi (朱洪實) and Huangfu Yu (皇甫遇).
[5] Shortly after, Zhu and Feng decided that they did not want to allow Shi to remain at Hedong for too long, and they also wanted to recall the eunuch Meng Hanqiong, who had been overseeing the governance of Tianxiong ever since Li Conghou was recalled from Tianxiong.
Li Congke then took his army and headed for Luoyang, announcing that all who surrendered to him would be forgiven, except Zhu and Feng.
Zhu, however, interpreted the command summoning him to be a sign that Li Conghou intended to punish him for his wrong advice, and committed suicide by jumping into a well.
Feng's wife and children were also killed, except a three-year-old son, who was hidden by his former subordinate Zhang Shousu (張守素).