In the heart of winter he hurried back, and took the Gauls by surprise by crossing the snows that lay thick on the wild waste of the Cebenna, which the Arverni had always considered as their impenetrable barrier throughout the winter. The towns quickly fell into his hands, and he was rapidly recovering all he had lost, when Vercingetorix, collecting his chief supporters, represented to them that their best hope would be in burning all the inhabited places themselves and driving off all the cattle, then lying in wait to cut off all the convoys of provisions that should be sent to the enemy, and thus starving them into a retreat. He said that burning houses were indeed a grievous sight, but it would be more grievous to see their wives and children dragged into captivity. To this all the allies agreed, and twenty towns in one district were burnt in a single day; but when they came to the city of Avaricum, now called Bourges, the tribe of Bituriges, to whom it belonged, entreated on their knees not to be obliged to destroy the most beautiful city in the country, representing that, as it had a river on one side, and a morass everywhere else, except at a very narrow entrance, it might be easily held out against the enemy, and to their entreaties Vercingetorix yielded, though much against his own judgment. Caesar laid siege to the place, but his army suffered severely from cold and hunger; they had no bread at all, and lived only on the cattle driven in from distant villages, while Vercingetorix hovered round, cutting off their supplies. They however labored diligently to raise a mount against a wall of the town; but as fast as they worked, the higher did the Gauls within raise the stages of their rampart, and for twenty- five days there was a most brave defense; but at last the Romans made their entrance, and slaughtered all they found there, except 800, who escaped to the camp of Vercingetorix. He was not disconcerted by this loss, which he had always expected, but sheltered and clothed the fugitives, and raised a great body of archers and of horsemen, with whom he returned to his own territory in Auvergne. There was much fighting around the city of Gergovia; but at length, owing to the revolt of the Aedui, another Gallic tribe, Caesar was forced to retreat over the Loire; and the wild peaks of volcanic Auvergne were free again.