Mithra, friend, originating in India, was a god of light who was translated into the attendant god of Ahura Mazdah in the light religion of Persia, from there he was adopted by the Romans as their deity Mithras. Generally, he is not regard as a sky god, but rather a personification of the fertilization power of warm, light air. According to the Avesta, he possesses 10,000 eyes and ears and rides in a chariot drawn by white horses.
In the dualistic Zoroastrianism, which effectively demoted him, Mithra, who represented truth, was concerned with the constant battle between light and dark forces. He was responsible for the keeping of oaths and contracts. He was born from a rock, according to legend, and engaged in a primeval struggle with Ahura Mazdah’s first creation, a wild bull, which he subdued and confined in a cave. The bull escaped, but was recaptured by Mithra, who slit it throat. The flowing of that blood gave plant life on earth. Ahriman, the power of darkness, is his chief adversary.
Mithra, though not generally worship alone, was an integral part of the Mithraic worship of Ahura Mazdah, where he acts as an intercessor between gods and men. In the Hellenic period he assume more of the role of a sun god. A.G.H.
Jordan, Michael, Encyclopedia of Gods, New York, Facts On File, Inc. 1993, p.p 166-167