Of St. Mark's Gospel the history is even more profoundly obscure. Papias, again the highest discoverable link of the Church tradition, says that St. Mark accompanied St. Peter to Rome as his interpreter; and that while there he wrote down what St. Peter told him, or what he could remember St. Peter to have said. Clement of Alexandria enlarges the story. According to Clement, when St. Peter was preaching at Rome, the Christian congregation there requested St. Mark to write a Gospel for them; St. Mark complied without acquainting St. Peter, and St. Peter when informed of it was uncertain whether to give or withhold his sanction till his mind was set at rest by a vision. Irenaeus, on the other hand, says that St. Mark's Gospel was not written till after the death of St. Peter and St. Paul. St. Chrysostom says that after it was written St. Mark went to Egypt and published it at Alexandria; Epiphanius again, that the Egyptian expedition was undertaken at the express direction of St. Peter himself. Thus the Church tradition is inconsistent with itself, and in all probability is nothing but a structure of air; it is bound up with the presence of St. Peter at Rome; and the only ground for supposing that St. Peter was ever at Rome at all is the passage at the close of St. Peter's First Epistle, where it pleased the Fathers to assume that the 'Babylon' there spoken of must have been the city of the Caesars. This passage alone, with the wild stories (now known to have originated in the misreading of an inscription) of St. Peter's conflict with Simon Magus in the presence of the emperor, form together the light and airy arches on which the huge pretences of the Church of Rome have reared themselves. If the Babylon of the Epistle was Babylon on the Euphrates--and there is not the slightest historical reason to suppose it to have been anything else--the story of the origin of St. Mark's Gospel perishes with the legend to which it was inseparably attached by Church tradition. Of St. John's Gospel we do not propose to speak in this place; it forms a subject by itself; and of that it is enough to say that the defects of external evidence which undoubtedly exist seem overborne by the overwhelming proofs of authenticity contained in the Gospel itself.