But although the existence of the British Isles was thus known at an early period to the classic writers under specific names, and some slender information acquired through the medium of the early tin trade as to their position and magnitude, it was not till the progress of the Roman arms and their lust of conquest had brought their legions into actual contact with the native population, that any information as to the inhabitants of these islands was obtained. [Sidenote: B.C. 55. Invasion of Julius Cæsar.] The invasion of Britain by Julius Cæsar in the year 55 before the Christian era, although it added no new territory to the already overgrown empire of the Romans, and was probably undertaken more with the view of adding to the military renown of the great commander, for the first time made the Romans acquainted with some of the tribes inhabiting that, to them, distant and almost inaccessible isle, and added distinctness and definiteness to their previously vague conception of its characteristics. Its existence was now not merely a geographical speculation, but a political fact in the estimation of those by whom the destinies of the world were then swayed—an element that might possibly enter into their political combinations. The conquests of Julius Cæsar in Britain, limited in extent and short-lived in duration, were not followed up. The policy of the subsequent emperors involved the neglect of Britain as an object of conquest; and, while it now assumed a more definite position in the writings of Greek and Roman geographers, they have left us nothing but the names of a few southern tribes and localities which do not concern the object before us, and a statement regarding the general population which is of more significance.