Gallic War

Although Caesar considered it ruinous to leave the war and the enemy, yet, being well aware what great evils generally arise from internal dissensions, lest a state so powerful and so closely connected with the Roman people, which he himself had always fostered and honored in every respect, should have recourse to violence and arms, and that the party which had less confidence in its own power should summon aid from Vercingetorix, he determined to anticipate this movement; and because, by the laws of the Aedui, it was not permitted those who held the supreme authority to leave the country, he determined to go in person to the Aedui, lest he should appear to infringe upon their government and laws, and summoned all the senate, and those between whom the dispute was, to meet him at Decetia. When almost all the state had assembled there, and he was informed that one brother had been declared magistrate by the other, when only a few persons were privately summoned for the purpose, at a different time and place from what he ought, whereas the laws not only forbade two belonging to one family to be elected magistrates while each was alive, but even deterred them from being in the senate, he compelled Cotus to resign his office; he ordered Convictolitanis, who had been elected by the priests, according to the usage of the state, in the presence of the magistrates, to hold the supreme authority.

Having pronounced this decree between [the contending parties], 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, 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, and then divided his army into two parts: he gave Labienus four legions to lead into the country of the Senones and Parisii ; and led in person six into the country of the Arverni, in the direction of the town of Gergovia , along the banks of the Allier . He gave part of the cavalry to Labienus and kept part to himself. Vercingetorix, on learning this circumstance, broke down all the bridges over the river and began to march on the other bank of the Allier .

When each army was in sight of the other, and was pitching their camp almost opposite that of the enemy, scouts being distributed in every quarter, lest the Romans should build a bridge and bring over their troops; it was to Caesar a matter attended with great difficulties, lest he should be hindered from passing the river during the greater part of the summer, as the Allier can not generally be forded before the autumn. Therefore, that this might not happen, having pitched his camp in a woody place opposite to one of those bridges which Vercingetorix had taken care should be broken down, the next day he stopped behind with two legions in a secret place; he sent on the rest of the forces as usual, with all the baggage, after having selected some cohorts, that the number of the legions might appear to be complete. Having ordered these to advance as far as they could, when now, from the time of day, he conjectured they had come to an encampment, he began to rebuild the bridge on the same piles, the lower part of which remained entire. Having quickly finished the work and led his legions across, he selected a fit place for a camp, and recalled the rest of his troops. Vercingetorix, on ascertaining this fact, went before him by forced marches, in order that he might not be compelled to come to an action against his will.

Caesar, in five days' march, went from that place to Gergovia , and after engaging in a slight cavalry skirmish that day, on viewing the situation of the city, which, being built on a very high mountain, was very difficult of access, he despaired of taking it by storm, and determined to take no measures with regard to besieging it before he should secure a supply of provisions. But Vercingetorix, 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; he ordered the rulers of the states, whom he had selected as his council of war, to come to him daily at the dawn, whether any measure seemed to require deliberation or execution. Nor did he allow almost any day to pass without testing in a cavalry action, the archers being intermixed, what spirit and valor there was in each of his own men. There was a hill opposite the town, at the very foot of that mountain, strongly fortified and precipitous on every side (which if our men could gain, they seemed likely to exclude the enemy from a great share of their supply of water, and from free foraging; but this place was occupied by them with a weak garrison): however, Caesar set out from the camp in the silence of night, and dislodging the garrison before succor could come from the town, he got possession of the place and posted two legions there, and drew from the greater camp to the less a double trench twelve feet broad, so that the soldiers could even singly pass secure from any sudden attack of the enemy.