Wang Chuzhi
Wang Chuzhi did have biological sons later, but he did not favor them, instead favoring Wang Du, who as he grew, was good at flattering his father and treachery. He established a new army and put Wang Du in charge of it. Among Wang Chuzhi's biological sons, apparently the oldest one was Wang Yu (), born of a concubine. Unhappy that Wang Chuzhi did not favor him, he fled to Li Keyong the military governor of Hedong Circuit (河東, headquartered in modern Taiyuan, Shanxi), and Li Keyong gave him a daughter in marriage, eventually promoting him to be the military prefect (團練使, "Tuanlianshi") of Xin Prefecture (新州, in modern Zhangjiakou, Hebei). As all of Wang Chuzhi's other sons were young, Wang Chuzhi made Wang Du the deputy military governor, and planned to pass the military governor office to him.