The battle of New Carthage took place in early 209 BC when a Roman army under Publius Cornelius Scipio successfully assaulted New Carthage, the capital of Carthaginian Iberia, which was defended by a garrison under Mago. The battle was part of the Second Punic War.
In 211 BC the Romans in Iberia (modern Spain and Portugal) were heavily defeated at the battle of the Upper Baetis. Reinforcements arrived in early 210 BC and Scipio brought further reinforcements when he took command late in the year. Scipio felt unable to draw into battle and defeat any of the three strong Carthaginian armies in the peninsula and so decided to strike at the material centre of Carthaginian power in Iberia: its capital, New Carthage. He arrived outside the city early in 209 BC and commenced his attack the next day. After defeating a Carthaginian force outside the walls, he pressed an attack on the east gate. Simultaneously men from the Roman ships attempted to escalade the wall to the south from the harbour area. Both attacks were repulsed.
In the afternoon Scipio renewed the attacks. Hard-pressed, Mago moved men from the north wall, which overlooked a broad, shallow lagoon. Anticipating this, Scipio sent a force of 500 men through the lagoon to scale the north wall, which they did unopposed. They fought their way to the east gate, opened it from inside and let in their comrades. New Carthage fell and was sacked, and Mago surrendered the citadel and the last of his troops. Vast amounts of precious metal and war materiel were seized. New Carthage became the logistics centre of the Roman war effort in Iberia and by 206 BC the Carthaginians had been expelled from the peninsula.
Background
When the Second Punic War broke out between Rome and Carthage in 218 BC, much of Iberia (modern Spain and Portugal) was controlled by Carthage or its allies. One of Rome's first actions of the war was to send an army to north-east Iberia. After seven years of mixed fortunes, the Romans hired 20,000 Celtiberian mercenaries to reinforce their regular army and advanced into southern Iberia. There they divided their forces into two armies. When the Celtiberians deserted, the Romans were heavily defeated in two separate battles in 211 BC.
The Roman general, and later consul, Gaius Claudius Nero brought over reinforcements in 210 BC and stabilised the situation, holding on to a small lodgement in north-east Iberia. Towards the end of 210 BC Publius Cornelius Scipio arrived with further Roman reinforcements to replace Nero in command of all Roman forces in Iberia. Scipio was extremely young by Roman standards for such a command: he was in his mid-twenties. He was unprecedentedly inexperienced to hold such a position by Roman standards of the time, never having held any senior positions.
Scipio commanded a total of 31,000 men: 28,000 infantry and 3,000 cavalry. There were three separate Carthaginian armies in Iberia, each as large as or larger than the Roman force. The Carthaginian armies were well away from the area occupied by the Romans: one was in central Iberia led by the overall Carthaginian commander in Iberia, Hasdrubal Barca; one near Gades (modern Cádiz); and the third in Lusitania (approximately modern Portugal). This division of Carthaginian forces made it difficult for them to mutually support each other. This would have allowed Scipio to easily march his army from the Roman base at Tarraco (modern Tarragona) to confront just one of these armies; probably the nearest, that under Hasdrubal in central Iberia.
At this time it was extremely difficult to force an unwilling opponent to give battle. Pitched battles were usually preceded by the two armies camping 2–12 kilometres (1–7 mi) apart for days or weeks; sometimes forming up in battle order each day. If either commander felt at a disadvantage, he might march off without engaging or decline to leave his fortified camp. Such a tactic could have led to an inconclusive campaign, at the end of which the Romans would have had to retreat, which would have demoralised their Iberian allies and probably have led to defections among them. Alternatively one of the other Carthaginian armies may have come to Hasdrubal's assistance, which would have raised the possibility of the Romans suffering a defeat similar to that of 211 BC. The defeats of 211 BC had badly damaged Rome's standing with the Iberian tribes. A rapid Roman victory would stiffen the morale of those tribes which had remained loyal to Rome and encourage others to come over. A continuing perception of Roman weakness would encourage defections.
Prelude
When he arrived in Iberia Scipio was set on adopting an immediate aggressive stance and so decided that instead of seeking battle with one of the Carthaginian armies, he would strike at the material centre of Carthaginian power in Iberia: its capital, New Carthage. New Carthage (known to the Romans as Carthago Nova) was founded in about 227 BC by the then ruler of Carthaginian Iberia, Hasdrubal the Fair. It possessed a large, deep-water, harbour with good facilities and was well positioned for travel to and from Carthage. There were productive silver mines in the nearby mountains. The city harbour was on a south-facing bay, with an entrance only about 600 metres (2,000 ft) wide; the city was on its northern shore. A hilly promontory separated the bay from a large, shallow, tidal lagoon to the north. The city was built on and between the five hills of this promontory. Its only connection to the mainland was a 300-metre-wide (300 yd) isthmus to the east. The lagoon was connected to the main bay by a narrow channel to the west of New Carthage. The city lay 450 kilometres (280 mi) south of the main Roman base.
Scipio sent spies to report back on the geography around New Carthage, its defences and its garrison. He learnt it was fortified by strong and high walls 3,700 metres (12,000 ft) long, which faced wide bodies of water for most of their length. There was a well-fortified gate on its eastern side, the main access to the city. The Carthaginians used New Carthage both as a mint and as their main treasury for Iberia. They also employed it as their main arsenal and military harbour for equipment and materiel for the war in Iberia, as well as holding prisoner there many Iberian captives who were hostage for their tribes' good behaviour. Its commander, Mago, had only 1,000 regular troops with which to defend the city, supplemented by what forces he could muster from the local populace; in the event a further 2,000 reasonably effective militia and an unknown number of irregulars. Scipio also reputedly learned details of how fordable the lagoon to the north was, in particular the effect of the tides and, possibly, the wind on it.
Once they reached New Carthage the Romans would only have a week or two to capture it before a Carthaginian army was likely to come to its aid. Yet it was highly unusual for well-fortified towns to be successfully stormed. If such places were taken it was usually either because of treachery from within, improbable in the case of New Carthage, or siege. But sieges normally lasted months and at least one Carthaginian army was sure to arrive before New Carthage was captured via siege.
Early in 209 BC, Scipio left 3,000 infantry and 300 cavalry to garrison Roman-occupied Iberia and marched south with the balance, 25,000 infantry and 2,500 cavalry. Thirty-five galleys set sail under Scipio's second in command, Gaius Laelius, intending to rendezvous with the main army at New Carthage. Such was the secrecy around these movements that when the Roman forces set out only Scipio and Laelius were aware of their destination; the other Roman commanders were enlightened at some point en route.
Battle
First assault
Arriving at New Carthage after a rapid march, the Romans established a camp on a hill in the middle of the isthmus connecting the city with the mainland, opposite the main gate. A rampart and ditch protected the rear (east) of the camp, but this was not repeated on the side facing the gate. Mago kept part of his regular troops in reserve in the citadel, which was in the west of the city, and the balance were posted on or near the southern wall. The 2,000 militia were stationed near the east gate and the rest of the town levy were issued with missiles and stationed all round the perimeter. Scipio made a stirring speech and the next morning the Romans attempted to storm the city: the Roman galleys assaulted the southern walls from the harbour while 2,000 picked legionaries made ready to attack the east gate and the walls to either side; both were supplied with ladders with which to attempt to escalade the walls.
During the Punic Wars it was usual for the garrisons of besieged towns and cities to initially give battle outside their walls, regardless of the relative sizes of the attacking and defending forces. Failure to do so was taken as an indication of the defender's weakness and lack of confidence by both sides. New Carthage was no exception and the 2,000 militia sallied from the east gate to counter-attack the Roman assault party. The Romans hung back, causing the initial fighting to develop nearer their camp than the city, perhaps 400 metres (1,300 ft) from the gate. Even so, given the narrowness of the isthmus, it was not possible for the Romans to readily bring their superior numbers to bear or to outflank the Carthaginians. At first the Carthaginian militia did well, but as the fighting continued the Romans were able to replace tired and wounded men from their large reserve in their camp; the Carthaginians possessed no such reserve. The Carthaginians began to be pushed back and eventually broke and fled.
The Romans pursued, inflicting heavy casualties on the Carthaginians as they struggled to retreat through the east gate. The Romans attempted to force their way through the gate before it could be closed, but failed. They then endeavoured to storm the walls on either side of the gate before the defenders could reorganise. This latter involved the attackers climbing the ladders which accompanied them amid missile fire from the defenders, then attempting to fight their way onto the walls. As the legionaries were attempting to do this, the marines from the Roman fleet were attempting the same thing against the south wall. The Carthaginian defenders were able to initially hold off these assaults and as the survivors of the militia sortie reinforced them on the walls Roman casualties mounted and success looked unlikely. Eventually, Scipio called off the attack.
Second assault
It was usual after a failed assault on fortifications for the attacking force to rest for several days before considering renewing their attack. To the Carthaginians' surprise, the Romans renewed their efforts that afternoon, with fresh troops and fresh supplies of scaling ladders. The galleys under Laelius again attacked the south wall, another force of infantry manoeuvred in the area of the channel to the west of the city – although this was a feint – and the main effort was again against the east gate and the nearby walls. Having expended most of their ammunition repelling the morning attacks, the Carthaginians were not able to respond as effectively to these; they were able to hold the walls with difficulty. Concerned, Mago moved reinforcements to the threatened areas, which resulted in the unthreatened northern wall being denuded of defenders. Scipio had maintained a reserve of 500 picked men and held them ready to move against the north wall, anticipating that threats from the other three cardinal directions would lead to its defences being weakened. To achieve its objective, this force would need to cross the broad lagoon.
The near-contemporary and usually reliable Greek historian Polybius wrote an account of the battle. According to the traditional translation of this he states that each evening the tide caused the water level in the lagoon north of New Carthage to lower to the extent that it was fordable. He continues that Scipio learnt of this during his gathering of intelligence in Tarraco and so timed his attacks as to make it probable that the wall bordering the lagoon was lightly held at the very time he wished to send a force to ford the lagoon and escalade the wall. The ancient Roman historian Livy, writing two centuries later, contradicts this – perhaps aware that tides do not operate on a 24-hour cycle – saying that the effect was because of a regular north wind piling up the waters of the lagoon each evening. Both of these accounts raise problems, not least why the Carthaginians were not aware of whatever changes took place and failed to take precautions.
Modern historians have offered several interpretations of Polybius's account and suggested different ways in which the level of the lagoon could have been artificially lowered. Among the latter have been its use as a fish farm or a salt evaporation pond, the level being controlled by sluices on the channel to the west of the city taking advantage of the 0.6 metres (2 ft 0 in) tidal range in the area. Benedict Lowe writes that the manoeuvres to the west of the city were not a feint, but the successful capture and opening of these sluices. J. H. Richardson, however, dismisses both Polybian and Livian accounts on grounds of hydrological and geological impossibility: tides at New Carthage are too small and slow to have drained the lagoon and there is insufficient space in which to produce a wind which could have blown out the million of litres of water contained. He instead suggests that the lagoon was itself largely fordable and that no hydrological event was necessary.