Mitra (Proto-Indo-Iranian: *mitrás) is the name of an Indo-Iranian divinity that came out of the Rigvedic Mitrá and Avestan Mithra.

The names, and some characteristics, of these established deities subsequently influenced other figures:

  • Maitreya, a vrddhi-derived form of Sanskrit mitra, a bodhisattva in Buddhist tradition.
  • Latin Mithras, the principal figure of the first-century Roman mystery cult of Mithraism, whose name derives from the Avestan theonym via Greek and some Anatolian intermediate.
  • In Hellenistic-era Asia Minor, Avestan Mithra was conflated with various local and Greek figures leading to several different variants of Apollo-Helios-Mithras-Hermes-Stilbon.
  • In Middle Iranian, the Avestan theonym evolved (among other Middle Iranian forms) into Sogdian Miši, Middle Persian and Parthian Mihr, and Bactrian Miuro (/mihru/). Aside from Avestan Mithra, these derivative names were also used for Greco-Bactrian Mithro, Miiro, Mioro, and Miuro.
  • Mithra, the "first messenger" of Iranian Manichaeans.

Indian religious texts

Both Vedic Mitra and Avestan Mithra derive from an Indo-Iranian common noun *mitra-, generally reconstructed to have meant "covenant, treaty, agreement, promise." This meaning is preserved in Avestan miθra "covenant". In Sanskrit and modern Indo-Aryan languages, ' means "friend", one of the aspects of bonding and alliance.

The Indo-Iranian reconstruction is attributed to Christian Bartholomae, and was subsequently refined by A. Meillet (1907), who suggested derivation from the Proto-Indo-European root *mey- "to exchange".

A suggested alternative derivation was *meh "to measure" (Gray 1929). Pokorny (IEW 1959) refined Meillet's *mei as "to bind". Combining the root *mei with the "tool suffix" -tra- "that which [causes] ..." (also found in man-tra-, "that which causes to think"), then literally means "that which binds", and thus "covenant, treaty, agreement, promise, oath" etc. Pokorny's interpretation also supports "to fasten, strengthen", which may be found in Latin moenia "city wall, fortification", and in an antonymic form, Old English (ge)maere "border, boundary-post".

Meillet and Pokorny's "contract" did however have its detractors. Lentz (1964, 1970) refused to accept abstract "contract" for so exalted a divinity and preferred the more religious "piety". Because present-day Sanskrit mitra means "friend", and New Persian mihr means "love" or "friendship", Gonda (1972, 1973) insisted on a Vedic meaning of "friend, friendship", not "contract".

Meillet's analysis also "rectified earlier interpretations" that such an association was implied in the Younger Avesta (since the 6th century BCE), that too was conclusively dismissed.<!-- "lays to rest in a closely argued and detailed way" --> Today, it is certain that "(al)though Miθra is closely associated with the sun in the Avesta, he is not the sun" and "Vedic Mitra is not either." the genuine Old Persian form being reconstructed as *Miça. (Kent initially suggested Sanskrit<!-- Quote: "Skt. mitra- 'friend' borrowed into Iranian as epithet of a divinity,..."--> but later attributes this false etymology to a role that Mithra (and the sun) played in the now extinct branch of Zoroastrianism known as Zurvanism.

Indian Mitra

Vedic Mitra is a prominent deity of the Rigveda distinguished by a relationship to Varuna, the protector of rta as described in hymn 2, Mandala 1 of Rigveda. Together with Varuna, he counted among the Adityas, a group of solar deities, also in later Vedic texts. Vedic Mitra is the patron divinity of honesty, friendship, contracts and meetings.

The first extant record of Indo-Aryan Mitra, in the form mi-it-ra-, is in the inscribed peace treaty of c. 1400 BC between Hittites and the Hurrian kingdom of the Mitanni in the area southeast of Lake Van in Asia Minor. Mitra appears there together with four other Indic divinities as witnesses and keepers of the pact.

Iranian Mithra

thumb|200px|[[Mithra (left) in a 4th-century investiture sculpture at Taq-e Bostan in western Iran.]]

In Zoroastrianism, Mithra is a member of the trinity of ahuras, protectors of asha/arta, "truth" or "[that which is] right". Mithra's standard appellation is "of wide pastures" suggesting omnipresence. Mithra is "truth-speaking, ... with a thousand ears, ... with ten thousand eyes, high, with full knowledge, strong, sleepless, and ever awake." (Yasht 10.7). As preserver of covenants, Mithra is also protector and keeper of all aspects of interpersonal relationships, such as friendship and love.

Related to his position as protector of truth, Mithra is a judge (ratu), ensuring that individuals who break promises or are not righteous (artavan) are not admitted to paradise. As also in Indo-Iranian tradition, Mithra is associated with (the divinity of) the sun but originally distinct from it. Mithra is closely associated with the feminine yazata Aredvi Sura Anahita, the hypostasis of knowledge.

Mithra in Commagene

upright|thumb|Mithras-Helios, in Phrygian cap with solar rays, with 1st century BC [[Antiochus I Theos of Commagene, found at Mount Nemrut, in present-day eastern Turkey]]

There is a deity Mithra mentioned on monuments in Commagene. According to the archaeologist Maarten Vermaseren, 1st&nbsp;century&nbsp;BC evidence from Commagene demonstrates the "reverence paid to Mithras" but does not refer to "the mysteries".