He was given the name Zhao Zheng, (personal name Ying Zheng). The name name Zheng (正) came from his month of birth Zhengyue, the first month of the Chinese lunar calendar;. The clan name of Zhao came from his father's lineage and was unrelated to either his mother's name or the location of his birth. (Song Zhong says that his birthday, significantly, was on the first day of Zhengyue.