Caesar (18.4-19.1)

To the noble work of victory Caesar added a nobler still, that of settling those of the Barbarians who had escaped alive from the battle (there were more than one hundred thousand of them), and compelling them to resume the territory which they had abandoned and the cities which they had destroyed. He did this because he feared that if the territory became vacant the Germans would cross the Rhine and occupy it.

His second war, directly in defence of the Gauls, was against the Germans,[*] although previously, in Rome, he had made their king Ariovistus an ally.[*] But they were intolerable neighbours of Caesar’s subjects, and if an opportunity presented itself it was thought that they would not remain quietly in their present homes, but would encroach upon and occupy Gaul.