《史记·十二本纪·孝武本纪》
常山王有罪被废黜，迁于房陵，皇帝就封他的弟弟为真定王，以延续对其祖先的祭祀，并把常山设置为郡。
常山王有罪，迁，天子封其弟于真定，以续先王祀，而以常山为郡。
The King of Changshan was dismissed from office due to his crimes and was exiled to Fangling. Now the emperor enfeoffed the king’s younger brother as the King of Zhending to continue the latter’s ancestral rituals and turned Changshan into a state.