About the same time the messenger despatched by Civilis came up with the cohorts of the Batavians and the Canninefates, while by the orders of Vitellius they were advancing towards Rome. At once, inflated with pride and haughtiness, they demanded, by way of remuneration for their march, a donative, double pay, and an increase in the number of cavalry, things indeed which Vitellius had promised, but which they now asked, not with the thought of obtaining them, but as a pretext for mutiny. Flaccus, by his many concessions, had produced no other effect but to make them insist with more energy on what they knew he must refuse. Treating him with contempt, they made their way towards Lower Germany, to join Civilis. Hordeonius, assembling the tribunes and centurions, asked their opinion as to whether he should use coercion with those who refused obedience. Soon, yielding to his natural timidity and to the alarm of his officers, who were troubled by the suspicious temper of the auxiliaries and by the fact that the ranks of the legions had been recruited by a hurried conscription, he resolved to confine his troops to the camp. Then, repenting of his resolve, and finding that the very men who had advised it now disapproved it, he seemed bent on pursuing the enemy, and wrote to Herennius Gallus, legate of the first legion, who was then holding Bonna, that he was to prevent the Batavians from crossing the Rhine, and that he would himself hang on their rear with his army. They might have been crushed, if Hordeonius, moving from one side, and Gallus from the other, had enclosed them between their armies. But Flaccus abandoned his purpose, and, in other despatches to Gallus, recommended him not to threaten the departing foe. Thence arose a suspicion that the war was being kindled with the consent of the legates, and that everything which had happened, or was apprehended, was due, not to the cowardice of the troops, or to the strength of the enemy, but to the treachery of the generals.
When the Batavians were near the camp at Bonna, they sent on before them delegates, commissioned to deliver to Herennius Gallus a message from the cohorts. It was to this effect: "We have no quarrel with the Romans, for whom we have so often fought. Wearied with a protracted and fruitless service, we long for our native land and for rest. If no one oppose us, our march will be harmless, but if an armed force encounter us, we will make a way with the sword." The soldiers prevailed upon the hesitating legate to risk the chances of a battle. Three thousand legionaries, some raw Belgian cohorts, and with them a mob of rustics and camp-followers, cowardly, but bold of speech before the moment of danger, rushed out of all the gates, thinking to surround the Batavians, who were inferior in number. But the enemy, being veteran troops, formed in columns, presenting on every side a dense array, with front, flanks, and rear secure. Thus they were able to break the thin line of our soldiers. The Belgians giving way, the legion was driven back, retreating in confusion on the entrenchments and the gates. It was there that the greatest slaughter took place. The trenches were heaped up with corpses. Nor was it only from the deadly blows of the enemy that they suffered;many perished in the crush and by their own weapons. The victorious army, who avoided the Colonia Agrippinensis, did not venture on any other hostile act during the remainder of their march, and excused the conflict at Bonna, alleging that they had asked for peace, and that when it was refused they had but looked to their own safety.
Civilis, who now on the arrival of these veteran cohorts was at the head of a complete army, but who was undecided in his plans, and still reflected on the power of Rome, made all who were with him swear allegiance to Vespasian, and sent envoys to the two legions which after their defeat in the previous engagement had retreated into the Old Camp, advising them to accept the same allegiance. Their reply was: "We do not follow the advice of traitors or enemies. Vitellius is our Emperor; to him we will retain our fealty and devote our swords till our last breath. Then let not a Batavian refugee affect to decide the destinies of Rome; let him rather await the merited penalty of his guilt." When this reply was delivered to Civilis, he was furious with anger, and hurried the whole Batavian nation into open war. The Bructeri and the Tencteri joined him, and messengers summoned all Germany to share in his plunder and his glory.
To meet the threatened dangers of the gathering war, the legates of the legions, Munius Lupercus and Numisius Rufus, strengthened their entrenchments and walls. The buildings, which during a long period of peace had grown up like a town near the camp, were destroyed, lest they might be useful to the enemy. Little care, however, was taken about the conveyance of supplies into the camp. These the generals allowed to be plundered; and so, what might long have sufficed for their necessities, was wantonly wasted in a few days.
Civilis, who occupied the centre of the army with the elite of the Batavian troops, wishing to add a new terror to his demonstration, covered both banks of the Rhine with columns of his German allies, while his cavalry galloped about the plains. At the same time the fleet was moved up the stream. Here were the standards of the veteran cohorts; there the images of wild beasts, brought out of the woods and sacred groves, under the various forms which each tribe is used to follow into battle, and these mingled emblems of civil and of foreign warfare utterly confounded the besieged. The extent of the entrenchment raised the hopes of the besiegers. Constructed for two legions, it was now held by not more than five thousand Roman soldiers. But there was with them a great number of camp-followers, who had assembled there on the disturbance of peace, and who could be employed in the contest.
