Fortunately for Rome, while she was thus a prey to terror and anxiety, her consul's nerves were strong, and he resolutely urged on his march towards Sena, where his colleague, Livius, and the praetor Portius were encamped; Hasdrubal's army being in position about half a mile to the north. Nero had sent couriers forward to apprise his colleague of his project and of his approach; and by the advice of Livius, Nero so timed his final march as to reach the camp at Sena by night. According to a previous arrangement, Nero's men were received silently into the tents of their comrades, each according to his rank. By these means there was no enlargement of the camp that could betray to Hasdrubal the accession of force which the Romans had received. This was considerable; as Nero's numbers had been increased on the march by the volunteers, who offered themselves in crowds, and from whom he selected the most promising men, and especially the veterans of former campaigns. A council of war was held on the morning after his arrival, in which some advised that time should be given for Nero's men to refresh themselves, after the fatigue of such a march. But Nero vehemently opposed all delay. "The officer," said he, "who is for giving time for my men here to rest themselves, is for giving time to Hannibal to attack my men, whom I have left in the camp in Apulia. He is for giving time to Hannibal and Hasdrubal to discover my march, and to manoeuvre for a junction with each other in Cisalpine Gaul at their leisure. We must fight instantly, while both the foe here and the foe in the south are ignorant of our movements. We must destroy this Hasdrubal, and I must be back In Apulia before Hannibal awakes from his torpor." [Livy, lib. xxvii. c. 45.] Nero's advice prevailed. It was resolved to fight directly; and before the consuls and praetor left the tent of Livius, the red ensign, which was the signal to prepare for immediate action, was hoisted, and the Romans forthwith drew up in battle array outside the camp.
Hasdrubal had been anxious to bring Livius and Porcius to battle, though he had not judged it expedient to attack them in their lines. And now, on hearing that the Romans offered battle, he also drew up his men, and advanced towards them. No spy or deserter had informed him of Nero's arrival; nor had he received any direct information that he had more than his old enemies to deal with. But as he rode forward to reconnoitre the Roman lines, he thought that their numbers seemed to have increased, and that the armour of some-of them was unusually dull and stained. He noticed also that the horses of some of the cavalry appeared to be rough and out of condition, as if they had just come from a succession of forced marches. So also, though, owing to the precaution of Livius, the Roman camp showed no change of size, it had not escaped the quick ear of the Carthaginian general, that the trumpet, which gave the signal to the Roman legions, sounded that morning once oftener than usual, as if directing the troops of some additional superior officer. Hasdrubal, from his Spanish campaigns, was well acquainted with all the sounds and signals of Roman war; and from all that he heard and saw, he felt convinced that both the Roman consuls were before him. In doubt and difficulty as to what might have taken place between the armies of the south, and probably hoping that Hannibal also was approaching, Hasdrubal determined to avoid an encounter with the combined Roman forces, and to endeavour to retreat upon Insubrian Gaul, where he would be in a friendly country, and could endeavour to re-open his communications with his brother. He therefore led his troops back into their camp; and, as the Romans did not venture on an assault upon his entrenchments, and Hasdrubal did not choose to commence his retreat in their sight, the day passed away in inaction. At the first watch of the night, Hasdrubal led his men silently out of their camp, and moved northwards towards the Metaurus, in the hope of placing that river between himself and the Romans before his retreat was discovered. His guides betrayed him; and having purposely led him away from the part of the river that was fordable, they made their escape in the dark, and left Hasdrubal and his army wandering in confusion along the steep bank, and seeking in vain for a spot where the stream could be safely crossed. At last they halted; and when day dawned on them, Hasdrubal found that great numbers of his men, in their fatigue and impatience, had lost all discipline and subordination, and that many of his Gallic auxiliaries had got drunk, and were lying helpless in their quarters. The Roman cavalry was soon seen coming up in pursuit, followed at no great distance by the legions, which marched in readiness for an instant engagement. It was hopeless for Hasdrubal, to think of continuing his retreat before them. The prospect of immediate battle might recall the disordered part of his troops to a sense of duty, and revive the instinct of discipline. He therefore ordered his men to prepare for action instantly, and made the best arrangement of them that the nature of the ground would permit.
Heeren has well described the general appearance of a Carthaginian army. He says: "It was an assemblage of the most opposite races of the human species, from the farthest parts of the globe. Hordes of half-naked Gauls were ranged next to companies of white clothed Iberians, and savage Ligurians next to the far-travelled Nasamones and Lotophagi. Carthaginians and Phoenici-Africans formed the centre; while innumerable troops of Numidian horse-men, taken from all the tribes of the Desert, swarmed about on unsaddled horses, and formed the wings; the van was composed of Balearic slingers; and a line of colossal elephants, with their Ethiopian guides, formed, as it were, a chain of moving fortresses before the whole army. Such were the usual materials and arrangements of the hosts that fought for Carthage; but the troops under Hasdrubal were not in all respects thus constituted or thus stationed. He seems to have been especially deficient in cavalry, and he had few African troops, though some Carthaginians of high rank were with him. His veteran Spanish infantry, armed with helmets and shields, and short cut-and-thrust swords, were the best part of his army. These, and his few Africans, he drew up on his right wing, under his own personal command. In the centre, he placed his Ligurian infantry, and on the left wing he placed or retained the Gauls, who were armed with long javelins and with huge broadswords and targets. The rugged nature of the ground in front and on the flank of this part of his line, made him hope that the Roman right wing would be unable to come to close quarters with these unserviceable barbarians, before he could make some impression with his Spanish veterans on the Roman left. This was the only chance that he had of victory or safety, and he seems to have done everything that good generalship could do to secure it. He placed his elephants in advance of his centre and right wing. He had caused the driver of each of them to be provided with a sharp iron spike and a mallet; and had given orders that every beast that became unmanageable, and ran back upon his own ranks, should be instantly killed, by driving the spike into the vertebra at the junction of the head and the spine. Hasdrubal's elephants were ten in number. We have no trustworthy information as to the amount of his infantry, but it is quite clear that he was greatly outnumbered by the combined Roman forces."
The tactic of the Roman legions had not yet acquired the perfection which it received from the military genius of Marius, [Most probably during the period of his prolonged consulship, from B.C. 104 to B.C. 101, while he was training his army against the Cimbri and the Teutons.] and which we read of in the first chapter of Gibbon. We possess in that great work an account of the Roman legions at the end of the commonwealth, and during the early ages of the empire, which those alone can adequately admire, who have attempted a similar description. We have also, in the sixth and seventeenth books of Polybius, an elaborate discussion on the military system of the Romans in his time, which was not far distant from the time of the battle of the Metaurus. But the subject is beset with difficulties: and instead of entering into minute but inconclusive details, I would refer to Gibbon's first chapter, as serving for a general description of the Roman army in its period of perfection; and remark, that the training and armour which the whole legion received in the time of Augustus, was, two centuries earlier, only partially introduced. Two divisions of troops, called Hastati and Principes, formed the bulk of each Roman legion in the second Punic war. Each of these divisions was twelve hundred strong. The Hastatus and the Princeps legionary bore a breast-plate or coat of mail, brazen greaves, and a brazen helmet, with a lofty, upright crest of scarlet or black feathers. He had a large oblong shield; and, as weapons of offence, two javelins, one of which was light and slender, but the other was a strong and massive weapon, with a shaft about four feet long, and an iron head of equal length. The sword was carried on the right thigh, and was a short cut-and thrust weapon, like that which was used by the Spaniards. Thus armed, the Hastati formed the front division of the legion, and the Principes the second. Each division was drawn up about ten deep; a space of three feet being allowed between the files as well as the ranks, so as to give each legionary ample room for the use of his javelins, and of his sword and shield. The men in the second rank did not stand immediately behind those in the first rank, but the files were alternate, like the position of the men on a draught board. This was termed the quincunx order. Niebuhr considers that this arrangement enabled the legion to keep up a shower of javelins on the enemy for some considerable time. He says: "When the first line had hurled its pila, it probably stepped back between those who stood behind it, who with two steps forward restored the front nearly to its first position; a movement which, on account of the arrangement of the quincunx, could be executed without losing a moment. Thus one line succeeded the other in the front till it was time to draw the swords; nay, when it was found expedient, the lines which had already been in the front might repeat this change, since the stores of pila were surely not confined to the two which each soldier took with him into battle.
"The same change must have taken place in fighting with the sword; which, when the same tactic was adopted on both sides, was anything but a confused MELEE; on the contrary, it was a series of single combats." He adds, that a military man of experience had been consulted by him on the subject, and had given it as his opinion, "that the change of the lines as described above was by no means impracticable; and in the absence of the deafening noise of gunpowder, it cannot have had even any difficulty with trained troops."
The third division of the legion was six hundred strong, and acted as a reserve. It was always composed of veteran soldiers, who were called the Triarii. Their arms were the same as those of the Principes and Hastati; except that each Triarian carried a spear instead of javelins. The rest of the legion consisted of light armed troops, who acted as skirmishers. The cavalry of each legion was at this period about three hundred strong. The Italian allies, who were attached to the legion, seem to have been similarly armed and equipped, but their numerical proportion of cavalry was much larger.
Such was the nature of the forces that advanced on the Roman side to the battle of the Metaurus. Nero commanded the right wing, Livius the left, and the praetor Porcius had the command of the centre. "Both Romans and Carthaginians well understood how much depended upon the fortune of this day, and how little hope of safety there was for the vanquished. Only the Romans herein seemed to have had the better in conceit and opinion, that they were to fight with men desirous to have fled from them. And according to this presumption came Livius the consul, with a proud bravery, to give charge on the Spaniards and Africans, by whom he was so sharply entertained that victory seemed very doubtful. The Africans and Spaniards were stout soldiers, and well acquainted with the manner of the Roman fight. The Ligurians, also, were a hardy nation, and not accustomed to give ground; which they needed the less, or were able now to do, being placed in the midst. Livius, therefore, and Porcius found great opposition; and, with great slaughter on both sides, prevailed little or nothing. Besides other difficulties, they were exceedingly troubled by the elephants, that brake their first ranks, and put them in such disorder, as the Roman ensigns were driven to fall back; all this while Claudius Nero, labouring in vain against a steep hill, was unable to come to blows with the Gauls that stood opposite him, but out of danger. This made Hasdrubal the more confident, who, seeing his own left wing safe, did the more boldly and fiercely make impression on the other side upon the left wing of the Romans." ["Historie of the World," by Sir Walter Raleigh, p. 946.]
But at last Nero, who found that Hasdrubal refused his left wing, and who could not overcome the difficulties of the ground in the quarter assigned to him, decided the battle by another stroke of that military genius which had inspired his march. Wheeling a brigade of his best men round the rear of the rest of the Roman army, Nero fiercely charged the flank of the Spaniards and Africans. The charge was as successful as it was sudden. Rolled back in disorder upon each other, and overwhelmed by numbers, the Spaniards and Ligurians died, fighting gallantly to the last. The Gauls, who had taken little or no part in the strife of the day, were then surrounded, and butchered almost without resistance. Hasdrubal, after having, by the confession of his enemies, done all that a general could do, when he saw that the victory was irreparably lost, scorning to survive the gallant; host which he had led, and to gratify, as a captive, Roman cruelty and pride, spurred his horse into the midst of a Roman cohort; where, sword in hand, he met the death that was worthy of the son of Hamilcar and the brother of Hannibal.
Success the most complete had crowned Nero's enterprise. Returning as rapidly as he had advanced, he was again facing the inactive enemies in the south, before they even knew of his march. But he brought with him a ghastly trophy of what he had done. In the true spirit of that savage brutality which deformed the Roman national character, Nero ordered Hasdrubal's head to be flung into his brother's camp. Eleven years had passed since Hannibal had last gazed on those features. The sons of Hamilcar had then planned their system of warfare against Rome, which they had so nearly brought to successful accomplishment. Year after year had Hannibal been struggling in Italy, in the hope of one day hailing the arrival of him whom he had left in Spain; and of seeing his brother's eye flash with affection and pride at the junction of their irresistible hosts. He now saw that eye glazed in death and, in the agony of his heart, the great Carthaginian groaned aloud that he recognised his country's destiny.
[Carthagini jam non ego nuntios
Mittam superbos. Occidit, occidit
Spes omnis et fortuna nostri
Nominis, Hastrubale interemto.—HORACE.]