Zhang Jiuling
Zhang Jiazhen was born in 666, during the reign of Emperor Gaozong. His family was from Pu Prefecture (蒲州, roughly modern Yuncheng, Shanxi), and traced its ancestry to the Jin Dynasty (266–420) chancellor Zhang Hua and his First Son (張祎) (張華 → 張祎 → 張輿 → 次惠 → 安之 → 宏策 ( 張緬 →...張九齡 Zhang Jiuling) → 絢 → 吒子 → 長度 → 俊興 → 思義 → 張俊義). who was originally from Fanyang (范陽, in modern Beijing), but his great-great-grandfather Zhang Zizha (張子吒) served as the secretary general of Hedong Commandery (河東, roughly modern Yuncheng, later converted into Pu Prefecture) for Tang Dynasty's predecessor Sui Dynasty, and therefore relocated his family to Hedong. Zhang Jiazhen's great-grandfather Zhang Changdu (張長度), grandfather Zhang Junxing (張俊興), and father Zhang Siyi (張思義) all served as minor officials for Tang. He had at least one younger brother, Zhang Jiayou (張嘉祐), and as Zhang Siyi died early, Zhang Jiazhen and Zhang Jiayou supported each other in their youths.