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 Menapii have been already mentioned,( 41) had at length, eluding the vigilance of their opponents by a feigned retreat, crossed in the vessels belonging to the Menapii--an enormous host, which is said, including women and children, to have amounted to 430,000 persons.
They still lay, apparently, in the region of Nimeguen and Cleves; but it was said that, following the invitations of the Celtic patriot party, they intended to advance into the interior of Gaul; and the rumour was confirmed by the fact that bands of their horsemen already roamed as far as the borders of the Treveri.
But when Caesar with his legions arrived opposite to them, the sorely- harassed emigrants seemed not desirous of fresh conflicts, but very ready to accept land from the Romans and to till it in peace under their supremacy.