The Rhine had become the boundary of the Roman empire against the Germans.

In Gaul, which was no longer able to govern itself, the Romans had hitherto ruled on the south coast, while lately the Germans had attempted to establish themselves farther up.

The recent events had decided that Gaul was to succumb not merely in part but wholly to the Roman supremacy, and that the natural boundary presented by the mighty river was also to become the political boundary.

The senate in its better times had not rested, till the dominion of Rome had reached the natural bounds of Italy--the Alps and the Mediterranean--and its adjacent islands.

The enlarged empire also needed a similar military rounding off; but the present government left the matter to accident, and sought at most to see, not that the frontiers were capable of defence, but that they should not need to be defended directly by itself.