The Second Punic War is undoubtedly one of the most famous ancient wars, often painted as the greatest obstacle to the rise of the Roman Republic. The first Punic war had ended with a Roman victory and a weakened Carthage. After years of war and with indemnities to pay, Carthage lacked the financial assets to pay for the mercenaries they had hired and who subsequently revolted against their former employers when the pay was not forthcoming and also received aid by the Libyan natives. The revolt was eventually crushed, with one notable battle outside Carthage's walls where the majority of Carthaginian citizens took part, a unique situation as most ethnic Carthaginians preferred to conduct trade or sail and instead paid others to fight their wars. Rome took advantage of the situation and seized the Carthaginian colonies in Sicily, Corsica and Sardinia, colonies which were controlled by the former Carthaginian mercenary garrisons, now in revolt. Due to this debacle, Carthage lost a major source of income. To recuperate the losses the Barcids, a prominent Carthaginian family of military renown, launched an invasion of Iberia supported by the cities of Carthage and Gader. Several tribes were subdued and more importantly rich silver mines were secured which greatly aided the Carthaginian economy. At the same time Rome was preoccupied with the Illyrian Wars, which probably kept them from interfering in Iberia. The Second Punic War began when Hannibal deliberately provoked Rome by attacking the city of Saguntum, a Roman ally.
With the war in motion Hannibal quickly marched his army from Saguntum towards Italy. He first crossed the Ebro River, marched through southern Gaul facing only light obstacles and then earned eternal fame when he crossed the Alps with his elephants. Then followed ten years of war throughout Italy with the famous battles of River Trebia, Lake Trasimene and his most legendary victory, Cannae. Even though Hannibal was victorious and his armies were bolstered by Gauls from the Po River valley and by Italian peoples opposed to Rome, he did not have the manpower to successfully assault Rome itself. In addition, the Romans sent an army to Carthaginian Iberia to disrupt the Barcids' seat of power and to tie up any possible Carthaginian reinforcements.
Then, in 208 BC, the brother of Hannibal, Hasdrubal managed to outmaneuver Publius Scipio in Iberia and marched towards Italy following the same route as Hannibal. Unlike his brother's journey, that of Hasdrubal went much smoother due to the constructions left behind by Hannibal, but also because this time the Gauls did not resist the Carthaginian army and many joined its ranks.
The Romans now had two Carthaginian armies on their soil, a terrifying prospect. The hastily elected consuls, Gaius Claudius Nero and Marcus Livius, were dispatched to face the armies of Hannibal and Hasdrubal respectively. Claudius Nero and Hannibal only had limited engagements against each other, as Hannibal tried to avoid a battle against Nero's 40000 troops. Marcus Livius though yielded ground cautiously to Hasrubal allowing him to cross the river Metaurus to the town of Sena. The situation changed when Hasdrubal dispatched messengers to Hannibal, requesting that their armies link up in south Umbria, and the messengers were captured by the Romans with the plans falling in to the hands of Claudius Nero. He immediately marched north with 7000 troops, 1000 of them cavalry, as the thought of the two Carthaginian armies uniting would be a serious threat to Rome itself.
Claudius Nero had made haste and quickly reached the army of Marcus Livius during nightfall. Livius' army was camped at Sena with the praetor Porcius. The consuls agreed to cooperate and with a numerical advantage, initiated a battle with Hasdrubal whose army was camped a half-mile north of the Roman army. The following morning the Romans drew themselves up for battle and the Carthaginians did the same. Hasdrubal quickly noticed that the Roman army seemed much larger than earlier and remembering hearing a trumpet in the Roman camp during night, a sound he had become accustomed to during his battles in Iberia, which heralded the arrival of an important Roman figure. He correctly concluded that he was facing both consuls. With the odds stacked against him, Hasdrubal withdrew from the field. The rest of the day was silent as the Romans did not wish to attack the Carthaginian camp fortifications. When dusk came, Hasdrubal quietly withdrew from the camp and began to march north back to Gaul where he could establish secure communications with Hannibal. However this was not to be, as Hasdrubal's guides deserted him early on and he found himself on the wrong side of the river Metaurus with no place to cross in sight. The night passed uneventfully and the morning saw his army confused and his Gallic troops drunk. With the Roman cavalry fast approaching and the Roman legions not far behind and with no river crossing nearby, Hasdrubal reluctantly prepared himself for battle.
Hasdrubal had a large army with him, but how large the sources differ. Appian says 55,000 troops with 15 elephants, Livy says 61,000 Carthaginian casualties, while Polybios puts the Carthaginian casualties at 10,000. Modern estimates suggest 30,000 troops. The Roman army seems to have numbered approximately 37,000 troops, 7,000 belonging to Claudius Nero's army, with the remaining consisting of four legions of Marcus Livius and the praetor Porcius. Outnumbering the Carthaginians in numbers alone, the Romans also had a distinct advantage in cavalry numbers.
Hasdrubal's army was made up of three “components”. First were his Iberian troops, which were his best, many of them veterans and there were also a few African troops of uncertain origin among these. Second was a large force of Ligurians and the third were the Gauls who had joined Hasdrubal's army on the march and was considered the most disorderly and who were drunk at the battle. Hasdrubal placed the Iberians on his right flank, the Ligurians in his centre and the drunk Gauls on the left, who he hoped would be shielded by the terrain in front of them, a deep ravine. He also had ten elephants in his army which was stationed in front of the Ligurians and Iberians.
The Romans advanced on the Carthaginian army in an orderly fashion, with Claudius Nero on the right flank opposing the Gauls, Porcius commanding the center and Marcus Livius on the left. Livius and Porcius initiated the battle by charging their troops against the Iberians and Ligurians, respectively. The battle was favorable at first to Hasdrubal, whose elephants caused confusion in Livius' ranks and the Iberians and Ligurians held their ground. Claudius Nero who was trying to traverse the terrain and reach the Gauls, saw the futility in the situation and instead took a large part of his force and swiftly marched to the extreme Roman left behind the troops of Marcus Livius and Porcius and swinging his troops around hammered into the Iberians' flank which caused the Iberians to rout and collapse into the Ligurians, who tried to stand their ground and were cut down to a man by the pursuing Romans. With their sober comrades gone, the Gauls, unfit for battle after their activities the night before, were slaughtered by the victorious Romans, eager for as large a victory as possible. Seeing the outcome of the battle, Hasdrubal charged into the Roman infantry and met a glorious, if pointless, death, most likely unwilling to let himself be taken captive. Sources indicate almost the entire Carthaginian army was cut down with Roman losses at between 2,000 and 8,000 dead.
The consuls showed no respect for a fallen adversary and had Hasdrubal's head cut off and later thrown into Hannibal's camp as a sign of his brother's defeat. It is also likely it was the first and only message Hannibal got that Hasdrubal actually was in Italy at all.
According to Lord Byron, Hannibal said at seeing his brother's decapitated head: “Rome would now be the mistress of the world". It is most likely an invention by the author, but the words do carry a meaning. Hannibal did not have a force strong enough to attack Rome itself and with his only reinforcements destroyed and with no aid coming from Carthage, which was embroiled in its own political conflicts, he could not launch an assault on the city of Rome, and thus the threat of Rome being conquered was effectively gone. While it has generally not been as well known as other battles, the battle of Metaurus was the turning point of the war, as the outcome was favoring Rome from now on, yet the most famous battles from the Second Punic War are undoubtedly the victories of Hannibal and the final battle of Zama, while it is only in historical circles the battle of Metaurus is properly recognized.
If Hasdrubal had linked up with his brother, the outcome could have been very different. With the extra troops and siege equipment Hasdrubal brought with him, Hannibal would have had the numbers to siege Rome and conquer it. Even if Hannibal would not have been able to conquer Rome, as some historians claim, the brothers' combined armies' presence in Italy would most likely have added to the political strife that was present in Rome and in addition, to the anxiety that lingered in Rome and throughout Italy. There are many theories as to what would have happened if the battle of Metaurus did not occur, however that the battle did happen was clearly in the best interests of Rome. Polybios writes that the festivities in Rome when the news reached the city were joyous and grand, and he also mentions that at first the Romans did not believe it, being accustomed to not having won a large significant battle so far during the war.