Or Zerdusht, the founder or reformer of the Parsee religion, of whom, though certainly a historical personage, nothing whatever is for certain known except that his family name was Spitama, that he was born in Bactria, and that he could not have flourished later than 800 B.C.; he appears to have been a pure monotheist, and not to be responsible for the Manichean doctrine of dualism associated with his name, as Zoroastrianism, or the institution of fire-worship.