At an earlier period, the viscount of Chu, intending to declare Shangchen his successor, consulted his chief minister Zishang about it. Zishang said, "Your lordship is not yet old. You are also fond of many [of your children]. Should you degrade him hereafter, he will make disorder. The succession in Chu has always been from among the younger sons. Morever, he has eyes [projecting] like a wasp's, and a wolf's voice;—he is capable of anything. You ought not to raise him to that position." The viscount did it however. 

But afterwards he wished to appoint his son Zhi instead, and to degrade Shangchen. Shangchen heard of his intention, but was not sure of it. He therefore told his tutor Pan Chong, and asked him how he could get certain information. Chong said, "Give a feast to her of Jiang [The viscount's sister], and behave disrespectfully to her." The prince did so, when the lady became angry, and cried out, "You slave, it is with reason that the king wishes to kill you, and appoint Zhi in your place." Shangchen told this to his tutor, saying, "The report is true.' Chong then said, "Are you able to serve Zhi?" "No." "Are you able to leave the State?" "No." "Are you able to do the great thing?" "Yes."

In winter, in the 10th month. Shangchen, with the guards of his palace, held the king in siege. The king begged to have bear's paws to eat before he died, which was refused him; and on Dingwei he strangled himself. The prince [immediately] gave him the title of Ling, but his eyes would not shut. He changed it to Cheng, and they shut. [Shangchen] took his place, [and is known as] king Mu. He gave the house where he had lived as the eldest son to Pan Chong, made him grand-tutor, and commander of the palace guards.