In spite of this, however, it is very difficult to say how Mithras originally became known to the Romans. Plutarch says indeed that his cult was first introduced by the Cilician pirates who were put down by Pompey[786]. This is not likely to be literally true; for the summary methods adopted by these sea-robbers towards their Roman prisoners hardly gave much time for proselytism, while most of the pirates whom Pompey spared at the close of his successful operations he deported to Achaea, which was one of the few places within the Empire where the Mithraic faith did not afterwards show itself. What Plutarch’s story probably means is that the worship of Mithras first came to Rome from Asia Minor, and there are many facts which go to confirm this. M. Cumont, the historian of Mithraism, has shown that, long before the Romans set foot in Asia, there were many colonies of emigrants from Persia who with their _magi_ or priests had settled in Asia Minor, including in that phrase Galatia, Phrygia, Lydia, and probably Cilicia[787]. When Rome began to absorb these provinces, slaves, prisoners, and merchants from them would naturally find their way to Rome, and in time would no doubt draw together for the worship of their national deities in the way that we have seen pursued by the worshippers of the Alexandrian Isis and the Jewish exiles. The _magi_ of Asia Minor were great supporters of Mithridates, and the Mithridatic wars were no doubt responsible for a large number of these immigrants.