Mithraism, a dynamic religion developed over the previous millennium, took root in the newly created Persian Empire and played an influential role in religious developments over the next thousand years.

By 500 b.c.e., Persia had become the largest empire the world had ever known. Its subject peoples had multiple religions, which were tolerated, and the Persians themselves had a well-developed belief system that had evolved over the previous millennium. This religion, Mithraism (also Mithrism), continued to evolve during the next thousand years and had a revolutionary impact on other Western religions. By the late Roman Empire, Mithraism was the most popular religion among Roman soldiers and a major competitor of Christianity. Zoroaster

Mithra emerged as an important deity in the world’s earliest religious texts. In the Indian Rigveda (also known as Ṛgveda, c. 1500-1000 b.c.e.; English translation, 1896-1897) and the later Persian Avesta (1000-600 b.c.e.), Mithra is the god who rewards those who keep their contracts and punishes those who violate their commitments. In an increasingly complex commercial world, Mithra played an important role in interactions between the universe of the gods and the mundane affairs of humans. In Old Iranian, the name Mithra means contract, and his name was invoked to make binding a fourteenth century b.c.e. Hittite-Mitanni treaty that was discovered in the 1907 excavation at Bogazköy, Turkey. The form that worship of Mithra took at this time is not known.

In the earliest religious texts, Mithra is also associated with the light of the sun. By 500 b.c.e., Mithra was considered second only to Ahura Mazda, the supreme god of cosmic light, good, truth, and righteousness who is locked in a cosmic battle with Ahriman, the god of evil and darkness who is considered by many scholars to be the prototype of the devil. To help wage this battle on earth, Mithra took human form before the advent of civilization by being born from a rock (which he himself formed by divine concentration) on December 25. He was attended by shepherds and magi (representative of earlier Persian animistic beliefs) bearing gifts. By the sixth century b.c.e., Mithra’s birth was attributed to the immaculate conception of the virgin mother goddess Anahita (who had first emerged in Persian religion as a fertility goddess).

In the earliest texts, Mithra is linked to the slaying of a sacred bull with a dagger. From the blood and body of the dying bull grew all food plants and animals useful to humankind. With the slaying of the bull, the battle between good and evil, one front in a cosmic conflagration, began on earth. As humankind developed, Ahriman sent droughts and a great flood; however, Mithra interceded during each disaster to save humankind. As the threat of humankind’s extinction vanished, Mithra ate a sacramental meal of bread, the body of the bull, and wine (haoma). He then ascended to heaven in a fiery chariot to continue the cosmic battle against the forces of evil as an intermediary between the forces of light and humankind.

Early Persian worship of Mithra appears to have involved sacrificing a bull; a cleansing involving the bull’s blood was an important part of the sacramental ritual. In the seventh century b.c.e., the prophet Zoroaster (also called Zarathustra) attacked this sacrificial practice and transferred many of Mithra’s powers to Mazda. Zoroaster created a belief system more lofty and abstract than Mithraism, but one still containing Mithra as a major lieutenant of Mazda and his chief intermediary on earth. Eternally watchful of all affairs on earth, Mithra would be the judger of souls at the last judgment when the good would receive eternal heavenly bliss and the evil would join Ahriman in a fiery hell. Starting with Darius the Great, Persian kings followed Zoroastrianism but tolerated the older Mithraic belief.

Mithraism remained a powerful belief in the Persian Empire and may have influenced the Hebrew concepts of heaven and hell and good versus evil after Cyrus the Great freed the Hebrews from the Babylonian captivity (538 b.c.e.). It coexisted with a multitude of eschatological beliefs during the succeeding Hellenistic Age, then spread rapidly after 100 c.e., becoming the major belief of the Roman army. Remains of Mithraic temples, usually in underground caves, can be found throughout the Roman Empire, including fringe areas such as Britain and the Rhine.

The exact impact of Mithraism on Judaism, Christianity, and Islam remains a source of considerable scholarly debate. That its impact was great is difficult to refute. Mithraism’s practices and doctrines—including a ritual of baptism, ceremonies involving a sacred meal, the concept of a virgin birth on December 25, sacredness of worship on Sundays, and practice of calling all initiates “brother” and priests “father”—are similar to those of Christianity, and in the fifth century c.e. the faith was a powerful rival to the newly expanding religion of Christianity. However, Mithraism’s division into separate religious communities lacking any central administration and its refusal to allow female initiates helped doom the belief to oblivion.

• Clauss, Manfred. The Roman Cult of Mithras: The God and His Mysteries. New York: Routledge, 2000. A most reliable and readable account of the Roman form of the Mithras cult based on recent research and new archaeological discoveries. Bibliography and indexes.
• Colpe, Carsten. “Development of Religious Thought.” In Vol. 3 of The Cambridge History of Iran, edited by Ehsan Yarshater. Vol. 3. New York: Cambridge University Press, 1983. A clear treatment of the historical evolution of Persian Mithraism.
• Cumont, Franz V. The Mysteries of Mithra. Translated by Thomas J McCormack. New York: Dover Publications, 1956. The landmark study of Mithraism, originally published in English in 1903, by the scholar who started Mithraic studies. Bibliographic footnotes.
• Hinnells, John R. Persian Mythology. New York: P. Bedrick Books, 1985. A very readable treatment of the religions and mythology of ancient Persia, most notably Mithraism and Zoroastrianism. Bibliography.
• Ulansey, David. The Origins of the Mithraic Mysteries: Cosmology and Salvation in the Ancient World. New York: Oxford University Press, 1989. A scholarly study of the development of mythologies related to Mithraism. Bibliography.

Cyrus the Great; Zoroaster. Mithraism