The imposing position of Caesar in Gaul depended essentially on the halo of victory that surrounded him; and this began to grow pale.  The conflicts around Avaricum, Caesar’s vain attempts to compel the enemy to fight, the resolute defence of the city and its almost accidental capture by storm bore a stamp different from that of the earlier Celtic wars, and had strengthened rather than impaired the confidence of the Celts in themselves and their leader.  Moreover, the new system of warfare—­the making head against the enemy in intrenched camps under the protection of fortresses—­had completely approved itself at Lutetia as well as at Gergovia.  Lastly, this defeat, the first which Caesar in person had suffered from the Celts crowned their success, and it accordingly gave as it were the signal for a second outbreak of the insurrection.  The Haedui now broke formally with Caesar and entered into union with Vercingetorix.  Their contingent, which was still with Caesar’s army, not only deserted from it, but also took occasion to carry off the depots of the army of Caesar at Noviodunum on the Loire, whereby the chests and magazines, a number of remount-horses, and all the hostages furnished to Caesar, fell into the hands of the insurgents.  It was of at least equal importance, that on this news the Belgae, who had hitherto kept aloof from the whole movement, began to bestir themselves.  The powerful canton of the Bellovaci rose with the view of attacking in the rear the corps of Labienus, while it confronted at Lutetia the levy of the surrounding cantons of central Gaul.  Everywhere else too men were taking to arms; the strength of patriotic enthusiasm carried along with it even the most decided and most favoured partisans of Rome, such as Commius king of the Atrebates, who on account of his faithful services had received from the Romans important privileges for his community and the hegemony over the Morini.  The threads of the insurrection ramified even into the old Roman province:  they cherished the hope, perhaps not without ground, of inducing the Allobroges themselves to take arms against the Romans.  With the single exception of the Remi and of the districts—­dependent immediately on the Remi—­ of the Suessiones, Leuci, and Lingones, whose peculiar isolation was not affected even amidst this general enthusiasm, the whole Celtic nation from the Pyrenees to the Rhine was now in reality, for the first and for the last time, in arms for its freedom and nationality; whereas, singularly enough, the whole German communities, who in the former struggles had held the foremost rank, kept aloof.  In fact, the Treveri, and as it would seem the Menapii also, were prevented by their feuds with the Germans from taking an active part in the national war.

Caesar’s Plan of War
Caesar Unites with Labienus