did not occur to them that the Eternal City had achieved her greatness and built her empire under the auspices of Jupiter and Mars. There can be little doubt that, if the step taken by Constantine had been postponed for a hundred years, we should not find the Goths and the Vandals professing Christianity at the beginning of the fifth century. * * * * * [Sidenote: IRELAND NOT ISOLATED] Among the independent neighbours of the Roman Empire, Ireland occupies a singular place as the only part of the Celtic world which had not been gathered under the sceptre of Rome.[9] It may be suspected that an erroneous opinion is prevalent, just because it lay outside the Empire, that this outlying island was in early times more separate and aloof from Europe than its geographical position would lead us to suppose. The truth is that we have but lately begun to realise the frequency and prevalence of intercourse by sea before historical records begin. It has been but recently brought home to us that hundreds and hundreds of years before the Homeric poems were created, the lands of the Mediterranean were bound together by maritime communication. The same thing is true of the northern seas at a later period. It is absurd to suppose that the Celtic conquerors of Britain and of Iverne burned their ships when they had reached the island shores and cut themselves off from intercourse with the mainland from which they had crossed. And we may be sure that it was not they who first established regular communications. We may be sure that the pre-Celtic peoples of south Britain and the Ivernians, who gave its name to Ireland, knew the waterways to the coasts of the continent. The intimate connexion of the Celts of Britain with their kinsfolk across the Channel is amply attested in Caesar’s history of the conquest of Gaul; and in the ordinary histories of Britain the political connexion, which even took the shape of a Gallo-British kingdom, has hardly been duly emphasised. Ireland was further, but not far. Constant relations between this island and Britain were inevitable through mere proximity, but there is no doubt that regular communication was also maintained with Gaul[10] and with Spain. Whatever weight may be allowed to the Irish semi-mythical traditions which point to ancient bonds between Ireland and Spain—and in judging them we must remember that the Ivernians are of the same Mediterranean race as the Iberians—it is, for the Celtic period, highly significant to find Roman geographers regarding Ireland as midway between Spain and Britain,[11] a conception which seems to point unmistakably to direct intercourse between Irish and Spanish ports. But the trade of Ireland with the Empire is noticed by Tacitus,[12] and is illustrated by the knowledge which Romans could acquire of its geography. Ptolemy, in the second century, gives an account of the island, which, disfigured though it is, and in many parts undecipherable through the