This explains why certain institutions and beliefs of the Persians had found imitators and adepts in the Greco-Oriental world long before the Romans had gained a foothold in Asia. Their influence was indirect, secret, frequently indiscernible, but it was certain. The most active agencies in the diffusion of Mazdaism as of Judaism seem to have been colonies of believers who had emigrated far from the mother country. There was a Persian dispersion similar to that of the Israelites. Communities of magi were established not only in eastern Asia Minor, but in Galatia, Phrygia, Lydia and even in Egypt. Everywhere they remained attached to their customs and beliefs with persistent tenacity.[10] When Rome extended her conquests into Asia Minor and Mesopotamia, the influence of Persia became much more direct. Superficial contact with the Mazdean populations began with the wars against Mithradates, but it did not become frequent and lasting until the first century of our era. During that century the empire gradually extended its limits to the upper Euphrates, and thereby absorbed all the uplands of Anatolia and Commagene south of the Taurus. The native dynasties which had fostered the secular isolation of those distant countries in spite of the state of vassalage to which they had been reduced disappeared one after another. The Flavians constructed through those hitherto almost inaccessible regions an immense network {140} of roads that were as important to Rome as the railways of Turkestan or of Siberia are to modern Russia. At the same time Roman legions camped on the banks of the Euphrates and in the mountains of Armenia. Thus all the little Mazdean centers scattered in Cappadocia and Pontus were forced into constant relation with the Latin world, and on the other hand the disappearance of the buffer states made the Roman and Parthian empires neighboring powers in Trajan's time (98-117 A. D.). From these conquests and annexations in Asia Minor and Syria dates the sudden propagation of the Persian mysteries of Mithra in the Occident. For even though a congregation of their votaries seems to have existed at Rome under Pompey as early as 67 B. C., the real diffusion of the mysteries began with the Flavians toward the end of the first century of our era. They became more and more prominent under the Antonines and the Severi, and remained the most important cult of paganism until the end of the fourth century. Through them as a medium the original doctrines of Mazdaism were widely propagated in every Latin province, and in order to appreciate the influence of Persia upon the Roman creeds, we must now give them our careful attention.