Mithraism, also known as the Mithraic mysteries or the Cult of Mithras, was a Roman mystery religion centered on the god Mithras. Although inspired by Iranian worship of the Zoroastrian divinity (yazata) Mithra, the Roman Mithras was linked to a new and distinctive imagery, and the level of continuity between Persian and Greco-Roman practice remains debatable.[a] The mysteries were popular among the Imperial Roman army from the 1st to the 4th century CE.[2]

According to Antonia Tripolitis, Roman Mithraism originated in Vedic India and picked up many features of the cultures which it encountered in its westward journey.[ba]

https://en.wikipedia.org/wiki/Mithraism

(http://www.autoadmit.com/thread.php?thread_id=5522259&forum_id=2#47614785)

Mithra, in ancient Indo-Iranian mythology, the god of light, whose cult spread from India in the east to as far west as Spain, Great Britain, and Germany. (See Mithraism.) The first written mention of the Vedic Mitra dates to 1400 BC. His worship spread to Persia and, after the defeat of the Persians by Alexander the Great, throughout the Hellenic world. In the 3rd and 4th centuries AD, the cult of Mithra, carried and supported by the soldiers of the Roman Empire, was the chief rival to the newly developing religion of Christianity. The Roman emperors Commodus and Julian were initiates of Mithraism, and in 307 Diocletian consecrated a temple on the Danube River to Mithra, “Protector of the Empire.”

https://www.britannica.com/topic/Mithra

(http://www.autoadmit.com/thread.php?thread_id=5522259&forum_id=2#47614786)