Religion Article :

supreme god in ancient Iranian religion, especially in the religious system of the Iranian prophet Zoroaster (7th century–6th century BC). Ahura Mazda was worshiped by the Persian king Darius I (reigned 522 BC–486 BC) and his successors as the greatest of all gods and protector of the just king. A major personality in the history of the religions of the world, Zoroaster has been the object of much attention for two reasons. On the one hand, he became a legendary figure believed to be connected with occult knowledge and magical practices in the Near Eastern and Mediterranean world in the Hellenistic Age (c. 300 BC-c. AD 300).

Ahura Mazda was probably the chief god of the pre-Zoroastrian pantheon. In both the religion of Zoroaster and that of Darius and Xerxes, he was worshiped as the supreme god, almost to the exclusion of all others. Having received a vision from Ahura Mazda, the Wise Lord, who appointed him to preach the truth, Zoroaster apparently was opposed in his teachings by the civil and religious authorities in the area in which he preached.