MITHRA. After Ahura Mazdā and together with Anāhitā, Mithra is one of the major deities of ancient Iran, one that later crossed the borders of the Iranian world to become the supreme god of a mystery religion popular throughout the Roman Empire. In the Avesta and the later Zoroastrian literature Mithra turns up frequently; indeed, an entire Avestan hymn is dedicated to him (Yashts 10). He was also the subject of the Mithrakāna, a great festival that took place annually in the seventh month of the Zoroastrian calendar, which was itself dedicated to him. He is known to us from many other sources: in the inscriptions of the Achaemenids, beginning with Artaxerxes II (404–359 BCE), he is mentioned and invoked together with Ahura Mazdā and Anāhitā; on the coins of the Kushan empire he is named as Mioro and is depicted as a solar deity; in Parthian...