There was even more looting and bloodshed on Caecina’s march. The 67 Helvetii, a Gallic tribe once famous as fighting men and still distinguished by the memory of their past, having heard nothing of Galba’s murder, refused to acknowledge the authority of Vitellius. This exasperated Caecina’s headstrong nature. Hostilities broke out owing to the greed and impatience of the Twenty-first legion, who had seized a sum of money which was being sent to pay the garrison of a fort in which the Helvetii used to keep native troops at their own expense. The Helvetii, highly indignant at this, intercepted a dispatch from the German army to the Pannonian legions, and kept a centurion and some men in custody. Greedy for battle, Caecina hastened to take immediate vengeance without giving them time for second thoughts. Promptly breaking up his camp, he proceeded to harry the country, and sacked a charming and much-frequented watering-place, which had grown during the long peace into the size and importance of a town. Instructions were sent to the Raetian auxiliaries to attack the Helvetii in the rear, while their attention was occupied with the legion.
Full of spirit beforehand, the Helvetii were terrified in the face 68 of danger. At the first alarm they had chosen Claudius Severus general, but they knew nothing of fighting or discipline and were incapable of combined action. An engagement with the Roman veterans would be disastrous; and the walls, dilapidated by time, could not stand a siege. They found themselves between Caecina and his powerful army on the one side, and on the other the Raetian auxiliaries, both horse and foot, and the whole fighting force of Raetia as well, trained soldiers well used to fighting. Their country was given over to plunder and massacre. Flinging away their arms, they wandered miserably between two fires. Wounded and scattered, most of them took refuge on the Boetzberg. But some Thracian auxiliaries were promptly sent to dislodge them. The German army, aided by the Raetians, pursued them through the woods, and cut them to pieces in their hiding-places. Many thousands were killed and many sold as slaves. Having completed the work of destruction, the army advanced in hostile array against Aventicum, their capital town, and were met by envoys offering surrender. The offer was accepted. Caecina executed Julius Alpinus, one of their chief men, as the prime instigator of the revolt. The rest he left to experience the clemency or cruelty of Vitellius.
It is hard to say whether these envoys found Vitellius or the army the more implacable. The soldiers clamoured for the destruction of the town, and shook their fists and weapons in the envoys’ faces: even Vitellius indulged in threatening language. Ultimately, however, Claudius Cossus, one of the envoys, a noted speaker who greatly enhanced the effect of his eloquence by concealing his skill under a well-timed affectation of nervousness, succeeded in softening the hearts of the soldiers. A mob is always liable to sudden changes of feeling, and the men were as sensible to pity as they had been extravagant in their brutality. Thus with streams of tears and importunate prayers for a better answer the envoys procured a free pardon for Aventicum.