In any other time, the fall of such a prestigious town as Avaricum could have ended there and then the destiny of any Gallic chief, but Vercingetorix had enough oratory talent and chutzpah to turn this disaster around and cement his own authority. He also had enough connections to ruin the alliances made by Caesar and threaten his back...

Vercingetorix saves his head

Vercingetorix managed to save his head and secure his authority by recalling everyone that his first intention was never to defend the city of Avaricum but to burn it down altogether in order to deprive its walls to the Romans:

he himself was not disheartened by receiving so severe a loss, and had not concealed himself, nor shunned the eyes of the people: and he was believed to possess greater foresight and sounder judgment than the rest, because, when the affair was undecided, he had at first been of opinion that Avaricum should be burnt, and afterward that it should be abandoned.

And he scoffed at the loss of a city, when the whole country was waking up to take up his side against the invaders:

he would soon compensate it by superior advantages; for that he would, by his exertions, bring over those states which severed themselves from the rest of the Gauls, and would create a general unanimity throughout the whole of Gaul, the union of which not even the whole earth could withstand, and that he had it already almost effected; that in the mean time it was reasonable that he should prevail on them, for the sake of the general safety, to begin to fortify their camp, in order that they might the more easily sustain the sudden attacks of the enemy.

His reputation not only intact but even growing, Vercingetorix sends fresh orders to pursue the war:

He takes care that those who fled to him on the storming of Avaricum should be provided with arms and clothes. At the same time that his diminished forces should be recruited, he levies a fixed quota of soldiers from each state, and defines the number and day before which he should wish them brought to the camp, and orders all the archers, of whom there was a very great number in Gaul, to be collected and sent to him. By these means, the troops which were lost at Avaricum are speedily replaced.

Caesar settles a score

It was already the end of winter and Caesar was ready for the fight, but his endeavour was postponed. His main allies, the tribe of the Aedui, whom he had almost single-handedly put in control of the whole affairs in Gaul, requested his wisdom to settle a legal case at the higher echelons of their hierarchy.

Caesar, not wishing to let the confederation of tribes he had formed, fester and autodestroy, summoned a meeting, settled the case as fast as possible and decided to resume the war:

he exhorted the Aedui to bury in oblivion their disputes and dissensions, and, laying aside all these things, devote themselves to the war, and expect from him, on the conquest of Gaul, those rewards which they should have earned

A map showing the extent of the influence of the confederation led by the Aedui tribe.

And by earning these rewards, Caesar made clear he expected some substantial help:

and send speedily to him all their cavalry and ten thousand infantry, which he might place in different garrisons to protect his convoys of provisions.

This done, Caesar divided his army in two. Four legions under commend of Labienus went to the country of the Senones and Parisii (Ile de France today), while he led in person the remaining 6 legions directly into the country of the Arverni, in the direction of the town of Gergovia, along the banks of the Allier.

When he learned about the intention of Caesar to attack the territory of his own people, Vercingetorix quickly acted:

he broke down all the bridges over the river and began to march on the other bank of the Allier.

For a while, Caesar was contained on the other side of the river, unable to cross because he could not ford it. He needed a bridge but Vercingetorix was carefully shadowing him from the other side of the river, decided not to let him rebuild one of the broken bridge.

Once again, the Romans proved their mastery at engineering. Caesar detailed secretly two legions to repair a bridge while attracting the Gauls as far away as possible from the work. As soon as the work was done, he made his troops cross it. Vercingetorix retreated and five days later, the Romans were in front of Gergovia.

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The betrayal

Vercingetorix retreated to Gergovia and made sure that it would not know the same fate as Avaricum and placed his troops carefully:

having pitched his camp on the mountain near the town, placed the forces of each state separately and at small intervals around himself, and having occupied all the hills of that range as far as they commanded a view [of the Roman encampment], he presented a formidable appearance

Seeing this, no wonder Caesar felt a little bit worried:

being built on a very high mountain, was very difficult of access, he despaired of taking it by storm

So, he seized a small hill, built a fort and waited for the reinforcements promised by the Aedui. And this is where the hand of Vercingetorix is showing once again: thanks to bribes from the Arverni, the own leader which Caesar had put at the head of the Aedui colluded and agreed to put at the head of the 10000 soldiers promised to Caesar in the hands of an ally of Vercingetorix. When the contingent came near Gergovia, this leader suddenly revealed his true allegiance and accused the Romans of having committed the most horrible crimes against the Aedui. It was false, but enough to break the spell of Caesar:

He points to the Roman citizens, who had accompanied them, in reliance on his protection. He immediately seizes a great quantity of corn and provisions, cruelly tortures them, and then puts them to death, sends messengers throughout the entire state of the Aedui, and rouses them completely by the same falsehood concerning the slaughter of their knights and nobles; he earnestly advises them to avenge, in the same manner as he did, the wrongs, which they had received.

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Caesar, who had always indulged the Aedui, was alarmed by this news and knew he could not afford to lose 10.000 men and let them join the enemy ranks. He therefore dispatched a few cohorts to slow down the advance and sent with them some of the own Aedui noblemen which had been allegedly killed by the Romans:

When they were recognized and the treachery [...] discovered, the Aedui began to extend their hands to intimate submission, and, laying down their arms, to deprecate death.

This crisis dealt with, Caesar turned back towards Gergovia.