Cao Rui, courtesy name Yuanzhong, was the second emperor of the state of Cao Wei during the Three Kingdoms period. His parentage is in dispute: his mother, Lady Zhen, was Yuan Xi's wife, but she later remarried Cao Pi, the first ruler of Wei. Based on conflicting accounts of his age, Pei Songzhi calculated that, in order to be Cao Pi's son, Cao Rui could not have been 36 when he died as recorded, so the recorded age was in error; late-Qing scholars Lu Bi (卢弼) and Mao Guangsheng (冒广生) argued instead that Cao Rui was Yuan Xi's son.