relations with Mazdeism in the strict form which this last assumed after the religious reforms of the Sassanian Shahs have never been elucidated, and M. Cumont seems to rely too much upon the later Avestic literature to explain everything that is obscure in the religion of Mithras. If we imagine, as there is reason to do, that Western Mithraism was looked upon by the Sassanian reformers as a dangerous heresy[976], the Roman Emperors would have an additional reason for supporting it; and it is significant that it was exactly those rulers whose wars against the Persians were most successful who seem to have most favoured the worship of the Persian god. When Trajan conquered Dacia, the great province between the Carpathians and the Danube now represented by Hungary and Roumania, he colonized it by a great mass of settlers from every part of the Roman Empire, including therein many Orientals who brought with them into their new home the worship of their Syrian and Asianic gods[977]. It was hence an excellent field for the culture of a universal and syncretic religion such as that of Mithras, and the great number of Mithraea whose remains have been found in that province, show that this religion must have received hearty encouragement from the Imperial Court. From its geographical position, Dacia formed an effective counterpoise to the growing influence upon Roman policy of the Eastern provinces, and it might have proved a valuable outpost for a religion which was always looked upon with hostility by the Greek-speaking subjects of Rome. Unfortunately, however, a religion which allies itself with the State must suffer from its ally’s reverses as well as profit by its good fortunes, and so the Mithraists found. When the Gothic invasion desolated Dacia, and especially when Valerian’s disaster enabled the Goths to gain a footing there which not even the military genius of Claudius could loosen, Mithraism received a blow which was ultimately to prove fatal. The abandonment of Dacia to the Goths and Vandals by Aurelian in 255 A.D., led to its replanting by a race whose faces were turned more to Constantinople than to Rome, and who were before long to be converted to Christianity _en masse_[978]. Diocletian and his colleagues did what they could to restore the balance by proclaiming, as has been said above, the “unconquered” Mithras the protector of their empire at the great city which is now the capital of the Austrian Empire; but the accession of Constantine and his alliance with the Christian Church some twenty years later, definitely turned the scale against the last god of Paganism. Although the Mithraic worship may have revived for a moment under the philosophic Julian, who was, as has been said, peculiarly addicted to it, it possessed no real power of recuperation, and was perhaps one of the first Pagan religions to be extinguished by the triumphant Christians[979]. In 377 A.D., Gracchus,