For other uses, see Amastris (disambiguation). Amestris (Greek: Άμηστρις, Amēstris, perhaps the same as Άμαστρις, Amāstris, from Old Persian Amāstrī-, "strong woman") was the wife of Xerxes I of Persia, mother of king Artaxerxes I of Persia. She was known to have been poorly regarded by ancient Greek historians.Amestris was the daughter of Otanes, one of the seven nobleman who killed the magus impersonator of the Persian king Bardiya in 522 BC.