Once introduced, however, the worship of Mithras spread like wild-fire. The legions from the first took kindly to it, and this is the less surprising when we find that many of them were recruited under the earliest emperors in Anatolian states like Commagene, where the cult was, if not indigenous, yet of very early growth[788]. Moreover the wars of the Romans against the Persians kept them constantly in the border provinces of the two empires, where the native populations not infrequently changed masters. The enemy’s town that the legions besieged one year might therefore give them a friendly reception the next; and there was thus abundant opportunity for the acquaintance of both sides with each others’ customs. When the Roman troops marched back to Europe, as was constantly the case during the civil wars which broke out on the downfall of the Julian house, they took back with them the worship of the new god whom they had adopted, and he thus became known through almost the whole of the Roman Empire[789]. “From the shores of the Euxine to the north of Brittany and to the fringe of the Sahara[790],” as M. Cumont says, its monuments abound, and, he might have added, they have been met with also in the Egyptian Delta, in Babylon, and on the northern frontiers of India. In our own barbarous country we have found them not only in London and York, but as far west as Gloucester and Chester and as far north as Carlisle and Newcastle[791]. The Balkan countries, like Italy, Germany, Southern France, and Spain, are full of them; but there was one part of the Roman Empire into which they did not penetrate freely. This was Greece, where the memories of the Persian Wars long survived the independence of the country, and where the descendants of those who fought at Salamis, Marathon, and Thermopylae would have nothing to do with a god coming from the invaders’ fatherland. It is only very lately that the remains of Mithras-worship have been discovered at the Piraeus and at Patras, in circumstances which show pretty clearly that it was there practised only by foreigners[792].