张昌宗
It is not known when Zhang Yizhi and Zhang Changzong were born. It is known that their father Zhang Xizang (張希臧) had, at one point, served as the census officer of Tang Dynasty's capital prefecture Yong Prefecture (雍州, roughly modern Xi'an, Shaanxi) and was a distant nephew of the chancellor Zhang Xingcheng. Their mother might be Lady Wei or Lady Zang.