Sisygambis was the mother of Darius III of Persia, whose reign was ended during the wars of Alexander the Great. After she was captured by Alexander at the Battle of Issus, she became devoted to him, and Alexander referred to her as "mother".
She may have been the daughter of king Artaxerxes II Memnon, or possibly of his brother Ostanes. If the latter, she married her own brother Arsames (an ancient Achaemenid tradition). She gave birth to Darius, Oxyathres, and possibly also Stateira I.
At the Battle of Issus (333 BC), Darius' army was routed and the Persian king fled the field, leaving his extended family, including his mother, his wife Stateira I, his children, and many others to the mercy of Alexander. Alexander captured them but treated them well. When Alexander the Great and Hephaestion went together to visit the captured Persian royal family, Sisygambis knelt to Hephaestion to plead for their lives, mistaking him for Alexander, because he was the taller, and both young men were wearing similar clothes. When she realized her mistake, she was acutely embarrassed, but Alexander reassured her with the words, "You were not mistaken, Mother; this man too is Alexander."
At the Battle of Gaugamela, Sisygamis and her family were kept in the baggage train behind Alexander's army. When the Persian army's Scythian cavalry broke though Alexander's forces to reach them, she allegedly refused to celebrate what appeared at first to be Persian victory.Quintus Curtius Rufus informs that Sisygambis could never forgive her son Darius for abandoning his family at Issus. After Darius was killed shortly following his defeat at Gaugamela, Alexander sent his body to her for burial. Called upon to mourn his death, she was reported to have said, I have only one son [Alexander] and he is king of all Persia.
She married her granddaughter, Stateira II, to Alexander in 324 BC, an event which was the centrepiece of the Susa weddings. She was left at Susa with tutors to teach her Greek, while Alexander pursued his conquests.