The westward and southward pressure of the Germans, then a very powerful and numerous people, was in full force in Cæsar's time, so much so that it seems certain that Cæsar's conquest of Gaul came just in time to stay and delay that tide of Germanic invasion which overran Gaul some centuries later. His first operations in Gaul were against the Helvetii, whose country corresponded to the modern Switzerland. He tells us that the Belgae are at continual war with the Germans along the Rhine, and also that the Helvetii in their own country fight almost daily battles with the Germans. In the first year of Cæsar's Gallic command, the Helvetii came to a decision to migrate from their country westward, and Cæsar's first campaign was conducted with the purpose of forcing them to return to their own country. He ordered them to return thither, he states, lest the Germans should take possession of the territory and thus become neighbours to the old Roman province in southern Gaul. Cæsar states plainly that the Belgae for the most part are of German origin; that in former times they had crossed the Rhine and dispossessed the Galli (here he used the name Galli as proper to the other inhabitants of Gaul in distinction from the Belgae). He indicates that, after this migration, they had offered a successful resistance to the invasion of the Cimbri and Teutones (between 113 and 102 B.C.). Modern Frenchmen, though their national name is in origin the name of a Germanic people, show a tendency, easily understood, to minimise the Germanic element in their composition, and M. D'Arbois de Jubainville, dealing with Cæsar's statement that the Belgae were mainly of Germanic origin, seeks to explain that this was true geographically not ethnographically, that they came from German lands but did not come of German ancestry. Against the plain statement of a contemporary observer, such explanations are always to be received with caution. In this instance, there is corroborative evidence which indicates that Cæsar's words are to be taken at their face value. Cæsar also tells us that the Condrusi, Eburones, Cærosi and Paemani "uno nomine Germani vocantur"--are called by the common name of Germans. Again he says that the Segni and Condrusi are "ex gente et numero Germanorum"--of the German nation and so accounted. Strabo, writing within a century of Cæsar, says that "the Nervii are a Germanic people." According to Cæsar, the Nervii had no commerce, avoided wine and other luxuries, and were fierce men of great valour. They led the rest of the Belgae in opposing him. Tacitus is a hardly less valid authority, for his father-in-law Agricola had been engaged in long campaigns against the Germans in the Rhine country. "The Treveri and the Nervii," he says, "are especially forward in asserting their German origin, as though by this boast of race to be distinguished from the pacific character of the Gauls." It was surely not a geographical origin that was claimed in such a way.