As the cult of Mithra bolted throughout the channels of military command and contact it was able to quickly reach the farthest regions of the Roman Empire. Rome itself became a prominent stronghold of the faith by the first century C.E. and mithraeums can be found as far north as Britain. Also with the traffic of oriental slaves, the faith was constantly reinforced by contact with believers from the east, which bolstered the mystery status of the religion; and this also openned up the faith to non-military Roman citizens through contact with their slaves. However, in its early stages within the Roman Empire, Mithraism was primarily a cult of the poor and lowlu classes - essentially a solder's and slave's religion, and it wasn't until the late second and third centuries C.E. that it had reached a high enough status that imperial interest began to be noticed. But even with the initiation of emperor Commodus (C.E. 180 - 192) it was no more than a passing fancy.

It wasn't until C.E. 274 that Mithraism gained a more prominent status when Aurilian declared the institution of a state cult of Sol Invictus (The Unconquerable Sun); he erected a magnificent temple to Mithra in Rome and coins of the time reflect the awesome power with which the Mithraic Unconquerable Son bore with the inscription declaring that the Sun is the Lord of the Empire. The Romans naturally associated Mithra with the sun as Mithra had since Zoroastrian times been associated with the rise of the sun - and indeed, the sun in Avestan scriptures was understood as his chariot - and now this symbolic fussion of Mithra and the Sun reflected Mithraism's final dialect - that is, it's Romanization. Finally in c. 307 Mithra's prominence within the Roman Empire was solidified by Diocletian by his public dedication to Sol Invictus Mithras, acclaiming him as "protector of the empire." However, Mithra's reign within the empire was not long - the pagan aristocracy began to fade under furthering Christian conversions and finally in 394 under Theodosius the cult all but disappeared.

However, Mithraism's descent from history - eventhough it's tenets survived into the middle ages in other sects such as that of Mani (Manicaenism) would not come without its bearing its final stamp upon the world - its impression upon Christian Doctrine.