By water there was an ancient connection between the west coast of India and both the Red Sea and Persian Gulf.  Traffic by the former route was specially active, from the time of Augustus to that of Nero.  Pliny[1076] complains that every year India and the East took from Italy a hundred million sesterces in return for spices, perfumes and ornaments.  Strabo[1077] who visited Egypt tells how 120 ships sailed from Myos Hormos (on the Red Sea) to India “although in the time of the Ptolemies scarcely any one would undertake this voyage.”  Muziris (Cranganore) was the chief depot of western trade and even seems to have been the seat of a Roman commercial colony.  Roman coins have been found in northern and even more abundantly in southern India, and Hindu mints used Roman models.  But only rarely can any one except sailors and merchants, who made a speciality of eastern trade, have undertaken the long and arduous journey.  Certainly ideas travel with mysterious rapidity.  The debt of Indian astronomy to Greece is undeniable[1078] and if the same cannot be affirmed of Indian mathematics and medicine yet the resemblance between Greek and Indian treatises on these sciences is remarkable.  Early Tamil poems[1079] speak of Greek wines and dumb (that is unintelligible) Roman soldiers in the service of Indian kings, but do not mention philosophers, teachers or missionaries.  After 70 A.D. this trade declined, perhaps because the Flavian Emperors and their successors were averse to the oriental luxuries which formed its staple, and in 215 the massacre ordered by Caracalla dealt a blow to the commercial importance of Alexandria from which it did not recover for a long time.  Thus the period when intercourse between Egypt and India was most active is anterior to the period when Christianity began to spread:  it is hardly likely that in 70 or 80 A.D. there were many Christians in Egypt.

As already mentioned, colonies of Christians from Persia settled on the west coast of India, where there are also Jewish colonies of considerable antiquity.  The story that this Church was founded by St. Thomas and that his relics are preserved in south India has not been found in any work older than Marco Polo.[1080] Cosmas Indicopleustes states that the Bishop of Kalliana was appointed from Persia, and this explains the connection of Nestorianism with southern India, for at that time the Nestorian Catholicos of Ctesiphon was the only Christian prelate tolerated by the Persian Government.

This Church may have had a considerable number of adherents for it was not confined to Malabar, its home and centre, but had branches on the east coast near Madras.  But it was isolated and became corrupt.  It is said that in 660 it had no regular ministry and in the fourteenth century even baptism had fallen into disuse.  Like the popular forms of Mohammedanism it adopted many Hindu doctrines and rites.  This implies on the one hand a considerable exchange of ideas:  on the other hand, if such reformers as