Three ways out of this difficulty might possibly be suggested by any humble imitator of Mr. Gladstone. First, the early English pirates may have learnt the word _castrum_ (they always used it as a singular) years before they ever came to Britain as settlers at all. For during the long decay of the empire, the corsairs of the flat banks and islets of Sleswick and Friesland made many a light-hearted plundering expedition upon the unlucky coasts of the maritime Roman provinces; and it was to repel their dreaded attacks that the Count of the Saxon Shore was appointed to the charge of the long exposed tract from the fenland of the Wash to the estuary of the Rother in Sussex. On one occasion they even sacked London itself, already the chief trading town of the whole island. During some such excursions, the pirates would be certain to pick up a few Latin words, especially such as related to new objects, unseen in the rude society of their own native heather-clad wastes; and amongst these we may be sure that the great Roman fortresses would rank first and highest in their barbaric eyes. Indeed, modern comparative philologists have shown beyond doubt that a few southern forms of speech had already penetrated to the primitive English marshland by the shores of the Baltic and the mouth of the Elbe before the great exodus of the fifth century; and we know that Roman or Byzantine coins, and other objects belonging to the Mediterranean civilisation, are found abundantly in barrows of the first Christian centuries in Sleswick--the primitive England of the colonists who conquered Britain. But if the word _castrum_ did not get into early English by some such means, then we must fall back either upon our second alternative explanation, that the townspeople of the south-eastern plains in England had become thoroughly Latinised in speech during the Roman occupation; or upon our third, that they spoke a Celtic dialect more akin to Gaulish than the modern Welsh of Wales, which may be descended from the ruder and older tongue of the western aborigines. This last opinion would fit in very well with the views of Mr. Rhys, the Celtic professor at Oxford, who thinks that all south-eastern Britain was conquered and colonised by the Gauls before the Roman invasion. If so, it maybe only the western Welsh who said Caer; the eastern may have said _castrum_, as the Romans did. In either of the latter two cases, we must suppose that the early English learnt the word from the conquered Britons of the districts they overran. But I myself have very little doubt that they had borrowed it long before their settlement in our island at all.