Zoroaster Zoroaster Zoroaster (, ; "Zōroastrēs"), (Persian: زرتشت pronounced as Zartusht) also known as Zarathustra (, ; "Zaraθuštra"), Zarathushtra Spitama, or Ashu Zarathushtra, was an ancient Persian prophet, spiritual leader and ethical philosopher who taught a spiritual philosophy of self-realization and realization of the Divine. His teachings challenged the existing traditions of the Indo-Iranian religion and later developed into the religion of Mazdayasna or Zoroastrianism. He inaugurated a movement that eventually became the dominant religion in Ancient Persia. He was a native speaker of Old Avestan and lived in the eastern part of the Iranian Plateau, but his exact birthplace is
Medes of the Indo-Iranian word "arta-" (lit. "truth") which is familiar from both Avestan and Old Persian and also examples of theophoric names containing "Maždakku" and also the name "Ahura Mazdā". Scholars disagree whether these are indications of Zoroastrian religion amongst the Medes. Diakonoff believes that "Astyages and perhaps even Cyaxares had already embraced a religion derived from the teachings of Zoroaster" which was not identical with doctrine of Zarathustra and Mary Boyce believes that "the existence of the Magi in Media with their own traditions and forms of worship was an obstacle to Zoroastrian proselytizing there". Boyce wrote that the