While Caesar was thus forming the Roman domain in the west by force of arms into a compact whole, he did not neglect to open up for the newly-conquered country—­which was destined in fact to fill up the wide gap in that domain between Italy and Spain-communications both with the Italian home and with the Spanish provinces.  The communication between Gaul and Italy had certainly been materially facilitated by the military road laid out by Pompeius in 677 over Mont Genevre;(40) but since the whole of Gaul had been subdued by the Romans, there was need of a route crossing the ridge of the Alps from the valley of the Po, not in a westerly but in a northerly direction, and furnishing a shorter communication between Italy and central Gaul.  The way which leads over the Great St. Bernard into the Valais and along the lake of Geneva had long served the merchant for this purpose; to get this road into his power, Caesar as early as the autumn of 697 caused Octodurum (Martigny) to be occupied by Servius Galba, and the inhabitants of the Valais to be reduced to subjection—­a result which was, of course, merely postponed, not prevented, by the brave resistance of these mountain-peoples.

And with Spain

To gain communication with Spain, moreover, Publius Crassus was sent in the following year (698) to Aquitania with instructions to compel the Iberian tribes dwelling there to acknowledge the Roman rule.  The task was not without difficulty; the Iberians held together more compactly than the Celts and knew better than these how to learn from their enemies.  The tribes beyond the Pyrenees, especially the valiant Cantabri, sent a contingent to their threatened countrymen; with this there came experienced officers trained under the leadership of Sertorius in the Roman fashion, who introduced as far as possible the principles of the Roman art of war, and especially of encampment, among the Aquitanian levy already respectable from its numbers and its valour.  But the excellent officer who led the Romans knew how to surmount all difficulties, and after some hardly-contested but successful battles he induced the peoples from the Garonne to the vicinity of the Pyrenees to submit to the new masters.

Fresh Violations of the Rhine-Boundary by the Germans
The Usipetes and Tencteri

One of the objects which Caesar had proposed to himself—­ the subjugation of Gaul—­had been in substance, with exceptions scarcely worth mentioning, attained so far as it could be attained at all by the sword.  But the other half of the work undertaken by Caesar was still far from being satisfactorily accomplished, and the Germans had by no means as yet been everywhere compelled to recognize the Rhine as their limit.  Even now, in the winter of 698-699, a fresh crossing of the boundary had taken place on the lower course of the river, whither the Romans had not yet penetrated.  The German tribes of the Usipetes and Tencteri whose attempts to cross the Rhine in the territory of the