In the mean time Lucterius the Cadurcan, having been sent into the country of the Ruteni, gains over that state to the Arverni. Having advanced into the country of the Nitiobriges, and Gabali, he receives hostages from both nations, and, assembling a numerous force, marches to make a descent on the province in the direction of Narbo . Caesar, when this circumstance was announced to him, thought that the march to Narbo ought to take the precedence of all his other plans. When he arrived there, he encourages the timid and stations garrisons among the Ruteni, in the province of the Volcae Arecomici, and the country around Narbo which was in the vicinity of the enemy; he orders a portion of the forces from the province, and the recruits which he had brought from Italy, to rendezvous among the Helvii who border on the territories of the Arverni.

These matters being arranged, and Lucterius now checked and forced to retreat, because he thought it dangerous to enter the line of Roman garrisons, Caesar marches into the country of the Helvii; although mount Cevennes , which separates the Arverni from the Helvii, blocked up the way with very deep snow, as it was the severest season of the year; yet having cleared away the snow to the depth of six feet, and having opened the roads, he reaches the territories of the Arverni, with infinite labor to his soldiers. This people being surprised, because they considered themselves defended by the Cevennes as by a wall, and the paths at this season of the year had never before been passable even to individuals, he orders the cavalry to extend themselves as far as they could, and strike as great a panic as possible into the enemy. These proceedings are speedily announced to Vercingetorix by rumor and his messengers. Around him all the Arverni crowd in alarm, and solemnly entreat him to protect their property, and not to suffer them to be plundered by the enemy, especially as he saw that all the war was transferred into their country. Being prevailed upon by their entreaties he moves his camp from the country of the Bituriges in the direction of the Arverni.

Caesar, having delayed two days in that place, because he had anticipated that, in the natural course of events, such would be the conduct of Vercingetorix, leaves the army under pretense of raising recruits and cavalry: he places Brutus, a young man, in command of these forces; he gives him instructions that the cavalry should range as extensively as possible in all directions; that he would exert himself not to be absent from the camp longer than three days. Having arranged these matters, he marches to Vienna by as long journeys as he can, when his own soldiers did not expect him. Finding there a fresh body of cavalry, which he had sent on to that place several days before, marching incessantly night and day, he advanced rapidly through the territory of the Aedui into that of the Lingones , in which two legions were wintering, that, if any plan affecting his own safety should have been organized by the Aedui, he might defeat it by the rapidity of his movements. When he arrived there, he sends information to the rest of the legions, and gathers all his army into one place before intelligence of his arrival could be announced to the Arverni. Vercingetorix, on hearing this circumstance, leads back his army into the country of the Bituriges; and after marching from it to Gergovia , a town of the Boii, whom Caesar had settled there after defeating them in the Helvetian war, and had rendered tributary to the Aedui, he determined to attack it.

This action caused great perplexity to Caesar in the selection of his plans; [he feared] lest, if he should confine his legions in one place for the remaining portion of the winter, all Gaul should revolt when the tributaries of the Aedui were subdued, because it would appear that there was in him no protection for his friends; but if he should draw them too soon out of their winter quarters, he might be distressed by the want of provisions, in consequence of the difficulty of conveyance. It seemed better, however, to endure every hardship than to alienate the affections of all his allies, by submitting to such an insult. Having, therefore, impressed on the Aedui the necessity of supplying him with provisions, he sends forward messengers to the Boii to inform them of his arrival, and encourage them to remain firm in their allegiance, and resist the attack of the enemy with great resolution. Having left two legions and the luggage of the entire army at Agendicum, he marches to the Boii.