Four military tribunes with consular authority were elected—Titus Quintius Pennus, from the consulship, Caius Furius, Marcus Postumius, and Aulus Cornelius Cossus. Of these Cossus held the command in the city. The other three, after the levy was held, set out to Veii, and were an instance how mischievous in military affairs is a plurality of commanders. By insisting each on his own plans, whilst they severally entertained different views, they left an opportunity open to the enemy to take them at advantage. For the Veientians, taking an opportunity, attacked their line whilst still uncertain as to their movements, some ordering the signal to be given, others a retreat to be sounded: their camp, which was nigh at hand, received them in their confusion and turning their backs. There was more disgrace therefore than loss. The state, unaccustomed to defeat, was become melancholy; they hated the tribunes, they insisted on a dictator, the hopes of the state now seemed to rest on him. When a religious scruple interfered here also, lest a dictator could not be appointed except by a consul, the augurs on being consulted removed that scruple. Aulus Cornelius nominated Mamercus Æmilius, and he himself was nominated by him master of the horse. So little did censorial animadversion avail, so as to prevent them from seeking a regulator of their affairs from a family unmeritedly censured, as soon as the condition of the state stood in need of genuine merit. The Veientians elated with their success, having sent ambassadors around the states of Etruria, boasting that three Roman generals had been beaten by them in an engagement, though they could not effect a public co-operation in their designs, procured volunteers from all quarters allured by the hope of plunder. The state of the Fidenatians alone determined on renewing hostilities; and as if it would be an impiety to commence war unless with guilt, after staining their arms with the blood of the new settlers there, as they had on a former occasion with that of the ambassadors, they join the Veientians. After this the leading men of the two states consulted whether they should select Veii or Fidenæ as the seat of war. Fidenæ appeared the more convenient. Accordingly, having crossed the Tiber, the Veientians transferred the war thither. There was great consternation at Rome. The army being recalled from Veii, and that same army dispirited in consequence of their defeat, the camp is pitched before the Colline gate, and armed soldiers are posted along the walls, and a suspension of all civil business is proclaimed in the forum, and the shops were closed; and every place becomes more like to a camp than a city.
Then the dictator, having sent criers through the streets, and having summoned the alarmed citizens to an assembly, began to chide them "that they allowed their minds to depend on such slight impulses of fortune, that, on the receipt of a trifling loss, which itself was sustained not by the bravery of the enemy, nor by the cowardice of the Roman army, but by the disagreement of the generals, they now dreaded the Veientian enemy, six times vanquished, and Fidenæ, which was almost taken oftener than attacked. That both the Romans and the enemies were the same as they were for so many ages: that they retained the same spirits, the same bodily strength, the same arms. That he himself, Mamercus Æmilius, was also the same dictator, who formerly defeated the armies of the Veientians and Fidenatians, with the additional support of the Faliscians, at Nomentum. That his master of the horse, Aulus Cornelius, would be the same in the field, he who, as military tribune in a former war, slew Lar Tolumnius, king of the Veientians, in the sight of both armies, and brought the spolia opima into the temple of Jupiter Feretrius. Wherefore that they should take up arms, mindful that with them were triumphs, with them spoils, with them victory; with the enemy the guilt of murdering the ambassadors contrary to the law of nations, the massacre of the Fidenatian colonists in time of peace, the infraction of truces, a seventh unsuccessful revolt. As soon as they should bring their camp near them, he was fully confident that the joy of these most impious enemies at the disgrace of the Roman army would not be of long continuance, and that the Roman people would be convinced how much better those persons deserved of the republic, who nominated him dictator for the third time, than those who, in consequence of his abolishing the despotism of the censorship, would cast a slur on his second dictatorship." Having offered up his vows and set out on his march, he pitches his camp fifteen hundred paces on this side of Fidenæ, covered on his right by mountains, on his left by the river Tiber. He orders Titus Quintius Pennus to take possession of the mountains, and to post himself secretly on some eminence which might be in the enemy's rear. On the following day, when the Etrurians had marched out to the field, full of confidence in consequence of their accidental success of the preceding day, rather than of their good fighting, he himself, having delayed a little until the senate brought back word that Quintius had gained an eminence nigh to the citadel of Fidenæ, puts his troops into motion and led on his line of infantry in order of battle in their quickest pace against the enemy: the master of the horse he directs not to commence the fight without orders; that, when it would be necessary, he would give the signal for the aid of the cavalry; then that he would conduct the action, mindful of his fight with the king, mindful of the rich oblation, and of Romulus and Jupiter Feretrius. The legions begin the conflict with impetuosity. The Romans, fired with hatred, gratified that feeling both with deeds and words, calling the Fidenatian impious, the Veientian robbers, truce-breakers, stained with the horrid murder of ambassadors, sprinkled with the blood of their own brother-colonists, treacherous allies, and dastardly enemies.
In the very first onset they had made an impression on the enemy; when on a sudden, the gates of Fidenæ flying open, a strange sort of army sallies forth, unheard of and unseen before that time. An immense multitude armed with fire and all blazing with fire-brands, as if urged on by fanatical rage, rush on the enemy: and the form of this unusual mode of fighting frightened the Romans for the moment. Then the dictator, having called to him the master of the horse and the cavalry, and also Quintius from the mountains animating the fight, hastens himself to the left wing, which, more nearly resembling a conflagration than a battle, had from terror given way to the flames, and exclaims with a loud voice, "Vanquished by smoke, driven from your ground as if a swarm of bees, will ye yield to an unarmed enemy? will ye not extinguish the fires with the sword? or if it is with fire, not with weapons, we are to fight, will ye not, each in his post, snatch those brands, and hurl them on them? Come, mindful of the Roman name, of the valour of your fathers, and of your own, turn this conflagration against the city of your enemy, and destroy Fidenæ by its own flames, which ye could not reclaim by your kindness. The blood of your ambassadors and colonists and the desolation of your frontiers suggest this." At the command of the dictator the whole line advanced; the firebrands that were discharged are partly caught up; others are wrested by force: the armies on either side are now armed with fire. The master of the horse too, on his part, introduces among the cavalry a new mode of fighting; he commands his men to take the bridles off their horses: and he himself at their head, putting spurs to his own, dashing forward, is carried by the unbridled steed into the midst of the fires: the other horses also being urged on carry their riders with unrestrained speed against the enemy. The dust being raised and mixed with smoke excluded the light from the eyes of both men and horses. That appearance which had terrified the soldiers, no longer terrified the horses. The cavalry therefore, wherever they penetrated, produced a heap of bodies like a ruin. A new shout then assailed their ears; and when this attracted the attention of the two armies looking with amazement at each other, the dictator cries out "that his lieutenant-general and his men had attacked the enemy on the rear:" he himself, on the shout being renewed, advances against them with redoubled vigour. When two armies, two different battles pressed on the Etrurians, now surrounded, in front and rear, and there was now no means of flight back to their camp, nor to the mountains, where new enemies were ready to oppose them, and the horses, now freed from their bridles, had scattered their riders in every direction, the principal part of the Veientians make precipitately for the Tiber. Such of the Fidenatians as survived, bend their course to the city of Fidenæ. Their flight hurries them in their state of panic into the midst of slaughter; they are cut to pieces on the banks; others, when driven into the water, were carried off by the eddies; even those who could swim were weighed down by fatigue, by their wounds, and by fright; a few out of the many make their way across. The other party make their way through the camp into the city. In the same direction their impetuosity carries the Romans in pursuit; Quintius more especially, and with him those who had just come down from the mountain, being the soldiers who were freshest for labour, because they had come up towards the close of the engagement.
These, after they entered the gate mixed with the enemy, make their way to the walls, and raise from their summit a signal to their friends of the town being taken. When the dictator saw this, (for he had now made his way into the deserted camp of the enemy,) he leads on the soldiers, who were now anxious to disperse themselves in quest of booty, entertaining a hope of a greater spoil in the city, to the gate; and being admitted within the walls, he proceeds to the citadel, whither he saw the crowds of fugitives hurrying. Nor was the slaughter in the city less than in the battle; until, throwing down their arms, begging nothing but their life, they surrendered to the dictator. The city and camp are plundered. On the following day, one captive being allotted to each horseman and centurion, and two to those whose valour had been conspicuous, and the rest being sold by auction, the dictator in triumph led back to Rome his army victorious and enriched with spoil; and having ordered the master of the horse to resign his office, he immediately resigned his own on the sixteenth day (after he had obtained it); surrendering in peace that authority which he had received during war and trepidations. Some annals have reported that there was a naval engagement with the Veientians at Fidenæ, a thing as difficult as it was incredible, the river even now not being broad enough for such a purpose; and at that time, as we learn from old writers, being considerably narrower: except that perhaps in disputing the passage of the river, magnifying, as will happen, the scuffle of a few ships, they sought the empty honour of a naval victory.
The following year had as military tribunes with consular power Aulus Sempronius Atratinus, Lucius Quintius Cincinnatus, Lucius Furius Medullinus, Lucius Horatius Barbatus. To the Veientians a truce for twenty years was granted, and one for three years to the Æquans, though they had solicited one for a longer term. There was quiet also from city riots. The year following, though not distinguished either by war abroad or by disturbance at home, was rendered celebrated by the games which had been vowed during the war, both through the magnificence displayed in them by the military tribunes, and also through the concourse of the neighbouring states. The tribunes with consular power were Appius Claudius Crassus, Spurius Nautilus Rutilus, Lucius Sergius Fidenas, Sextus Julius Iulus. The exhibition, besides that they had come with the public concurrence of their states, was rendered still more grateful to the strangers by the courtesy of their hosts. After the games seditious harangues were delivered by the tribunes of the commons upbraiding the multitude; "that stupified with admiration of those persons whom they hated, they kept themselves in a state of eternal bondage; and they not only had not the courage to aspire to the recovery of their hopes of a share in the consulship, but even in the electing of military tribunes, which elections lay open to both patricians and commons, they neither thought of themselves nor of their party. That they must therefore cease feeling surprised why no one busied himself about the interests of the commons: that labour and danger would be expended on objects whence emolument and honour might be expected. That there was nothing men would not attempt if great rewards were proposed for those who make great attempts. That any tribune of the commons should rush blindly at great risk and with no advantage into contentions, in consequence of which he may rest satisfied that the patricians against whom he should strive, will persecute him with inexpiable war, whilst with the commons in whose behalf he may have contended he will not be one whit the more honoured, was a thing neither to be expected nor required. That by great honours minds became great. That no plebeian would think meanly of himself, when they ceased to be despised by others. That the experiment should be at length made in the case of one or two, whether there were any plebeian capable of sustaining a high dignity, or whether it were next to a miracle and a prodigy that any one sprung from the commons should be a brave and industrious man. That by the utmost energy the point had been gained, that military tribunes with consular power might be chosen from among the commons also. That men well approved both in the civil and military line had stood as candidates. That during the first years they were hooted at, rejected, and ridiculed by the patricians: that at length they had ceased to expose themselves to insult. Nor did he for his part see why the law itself might not be repealed; by which that was made lawful which never could take place; for that there would be less cause for blushing at the injustice of the law, than if they were to be passed over through their own want of merit."