When the first news reached Rome of the catastrophe suffered by its army, the inhabitants did not yet know that even these few soldiers had survived. The State had placed unprecedented resources of men and material in the hands of the consuls to confront the enemy. Instead of the anticipated victory this had produced another defeat, far worse in scale even than Trebia or Trasimene, both of which had still shocked a population accustomed to victory. Panic gripped the city, people fearing both their own future and the fate of family members with the army. The depleted Senate met to debate their course of action, and it was Fabius Maximus who persuaded the senators to restrict public mourning and post guards at all the gates to prevent panicked flight. As importantly, scouts were sent out along the main roads to the south to seek any news of Hannibal. That was the vital question: what was the victorious enemy going to do now?6
Livy pictured the scene as Hannibal’s officers rode across the battlefield after the fighting: Clustered around Hannibal the rest congratulated him on his victory, and suggested that, since he had concluded so great a war, he should allow himself and his weary soldiers to rest for the remainder of the day and the following night. Marhabal, the cavalry leader, reckoned that they ought not to delay. ‘No,’ he said, 'so that you will appreciate what this battle has achieved, in five days time you will feast as a victor on the Capitol! Follow on! I shall go ahead with the cavalry, so that they will only hear of our approach after we have arrived.' This idea was too great and joyful for Hannibal to grasp immediately. And so he praised Marhabal's attitude; yet he needed time to consider his counsel. Then Maharbal said, 'Truly the gods do not give everything to the same man: you know how to win a victory, Hannibal, but you do not know how to use one.' This day's delay is widely believed to have saved the City and the empire.7
It is especially unfortunate that Polybius’ surviving account breaks off after Cannae and we do not have his discussion of Hannibal's subsequent actions. Livy’s view that Hannibal missed the opportunity of winning the war by not immediately moving on Rome has provoked varied comment. Some, including such notable soldiers as Field Marshal Montgomery, have agreed with the comment Livy attributed to Maharbal that Hannibal did not know how to a use a victory. Sometimes it is suggested that the Carthaginian army was ill prepared for siege warfare and the blame for this is laid at Hannibal’s door, the claim being that it prevented him from finishing the campaign. Others, especially in recent years, have rejected Livy’s view, claiming that a drive on Rome would have been difficult and unlikely to succeed, citing both practical and strategic arguments. Cannae is over 400km from Rome and only a small force of cavalry could even have dreamed of completing the journey in a mere five days. Advocates of this view argue that Rome was not undefended at this time, since sufficient troops could have reached the city before Hannibal. There may have been two 'urban' legions already in the process of being raised at Rome, whilst a detachment of 1,500 men was at Ostia and a legion destined to serve as marines with the fleet at Teanum. Another suggestion is that Hannibal simply could not have supplied his army if it had moved against Rome and then been forced to mount an assault or siege. The Carthaginians' lack of enthusiasm for sieges was not the result of lack of knowledge, but a result of Hannibal's desire never to be tied down in one place for the months necessary to reduce a strong city. Finally, that Hannibal did not move on Rome in 217 after Trasimene or 216 after Cannae, and only did so in 212 in an effort to draw the Romans away from his allies at Capua, is taken as proof that his plan never included the capture of the city itself. Instead Rome was to be persuaded to surrender by battlefield defeats and the break-up of its network of allies. In the weeks after Cannae this strategy would begin to bear fruit as much of Southern Italy defected to the Carthaginians.8
Although these claims are apparently plausible, many questionable assumptions underlie them. There is for instance a tendency to inflate the number and quality of troops available to defend Rome. We do not really know, for instance, whether the two urban legions had already been raised and organized by August. Similarly, whilst keeping his men and animals properly supplied is one of the first requirements of a commander, risks could well be taken in the short term if the military situation warranted it. Had Hannibal actually wanted to march on Rome, then it is unlikely that worries over supply would have prevented him. The central question is not whether or not he could then have captured the city by siege or direct attack, but whether the Romans would have resisted him at all. It was extremely difficult to capture a large and fortified city by assault in this period and neither the Romans nor the Carthaginians enjoyed much success whenever they made the attempt. Sieges were more likely to succeed, but took months or even years, the eight month siege of Saguntum being not untypical. Had the Romans resisted with even a garrison significantly smaller than some scholars believe was available, then Hannibal would be unlikely to have taken Rome and this failure would have robbed him of much of the prestige gained at Cannae. Yet this assumes that the Romans, confronted by the enemy outside their walls and with recent catastrophe in their mind, would have fought and not simply capitulated in despair. That they acted so nonchalantly at the approach of the Punic army in 212, even auctioning off the plot of land on which Hannibal had pitched his camp and selling it for the full value, does not mean that they would have behaved in the same way in 216. The situation four years later was much more favourable for the Romans, who by that time had several strong, experienced armies in the field.9
Perhaps before closing this discussion of what Hannibal should, or should not, have done in the aftermath of Cannae, it is worth considering what he actually did. For some time he remained near the site of the battle, burying his many dead and caring for the wounded, and according to most versions also granting honourable burial to Paullus. Ten representatives were chosen from amongst the 8,000 Roman citizens held prisoner.
These were to go to Rome and confirm the arrangements for their ransom already offered by Hannibal. Such negotiations to regulate the frequent ransom or exchange of prisoners appear to have been common throughout the First and Second Punic Wars, although they usually receive indirect mention in our sources. In this case, Hannibal sent with the ten captives one of his own staff, a certain Carthalo, probably the same man described elsewhere as the cavalry commander. He was sent with the express role of beginning negotiations if the Romans seemed at all inclined to seek peace.10
It was not at all unusual to begin the negotiations that would end a war under cover of talks dealing with the return of prisoners or retrieval of bodies. The majority of wars, especially between civilized states, were ended by negotiation, one side conceding defeat and accepting terms which acknowledged this, probably involving their giving up land or allies, paying a subsidy to the victor, and returning captives free whilst paying heavily for their own. Hannibal clearly entertained strong hopes that the Romans would now be ready to negotiate. In three years he had smashed successive armies sent against him, marching wherever he wished in Italy. Roman and allied casualties already totalled at least 100,000 men, well over a tenth of the Republic’s military manpower, if the Romans could excuse their earlier defeats as a product of poor preparation, Cannae had been a trial of strength which they had carefully made ready for and actively sought. What more demonstration of Hannibal and Carthage's overwhelming superiority did the Romans require?11
A view of part of the Sacra Via, the important ceremonial path into the centre of Rome as it passes through the Forum. Very few of the visible remains date to the third century BC. Yet this was already the heart of the City.
The Romans had a short breathing space before the prisoners' representatives and Hannibal arrived. A dispatch arrived from Varro, informing the Senate that he was in the process of re-forming a force of about 10,000 men at Canusium. The report dispelled initial rumours that the entire army had been wiped out, but also gave details of the actual losses suffered at Cannae, which were only a little less appalling. Most families were in mourning, but the earlier restrictions on public displays of grief were enforced. The mood in the city remained on the verge of hysteria and, as after earlier disasters, fears developed that the proper rites to honour and propitiate the gods had been neglected. Two Vestal Virgins were accused of breaking their vows of chastity and condemned to the traditional punishment of being buried alive, although one committed suicide to avoid this fate. One of the girls' alleged lovers was flogged so badly that he died as a result. A delegation led by Fabius Pictor, later to become Rome's first prose historian, was sent to the great shrine of Apollo at Delphi to consult the oracle and gain guidance for how Rome could propitiate the gods and bring an end to the disasters besetting the city. In the meantime, a consultation of the Sybilline Books led to one of the few instances of human sacrifice ever practised at Rome; a Greek man and woman and a Gallic man and woman, presumably slaves, were buried alive under the Forum Boarium - the oldest of Rome's markets, which suggests that the rite was very ancient.
There was more bad news from Sicily where Rome's ally Syracuse was under threat from a Punic fleet. Yet the Senate began to plan for the future. Varro was instructed to return to the city once the experienced praetor Marcus Claudius Marcellus arrived to take over his army. Marcus Junius Pera was appointed dictator, with Tiberius Sempronius Gracchus (soon to be twice consul and prove himself a gifted commander) as his Magister Equitum. This pair immediately began to levy new legions, taking men as young as 17 and also purchasing 8,000 slaves who were freed and enlisted. In time an army of four legions was created, armed in part from trophies, mostly Gallic weapons and armour, taken from the temples where they had been placed by triumphing generals in recent decades. Only 1,000 Roman cavalry could be raised, testifying to the heavy losses suffered by the equestrian order in the last two years. Rome was beginning to rebuild her strength, but this process would take a very long time. The mood became increasingly defiant, and when Varro returned to the city he was given something close to a hero's welcome, the Senate publicly thanking him ‘for not having despaired of the Republic'.12
The Roman Senate held its nerve, perhaps encouraged by the activity it had set in motion. When news arrived of the approaching delegation of prisoners’ representatives and Carthalo, the senate's response was immediate and unequivocal. Carthalo enjoyed the sanctity of an ambassador so was not harmed, but a lictor (one of the attendants of a Roman magistrate) was sent from the dictator to inform him that he would not be received and must depart from Roman territory before nightfall. There would be no negotiation with the enemy. The Romans had responded in exactly the same way earlier in the century when King Pyrrhus of Epirus had smashed their army in battle and sent an embassy to begin the discussion of a negotiated peace. The Romans were willing to negotiate only as victors, and demanded the admission of absolute defeat from their enemies even when this did not reflect the actual military situation. The Senate's response to the prisoners' requests matched this unyielding attitude. Not only did the State refuse to ransom them, but it also banned the men's families from raising the money privately. Livy noted that there were conflicting accounts of the fate of the ten delegates, but the most popular version was that they obeyed their oath to return to the enemy's camp and death or slavery, the Senate forcibly sending back those individuals who tried to escape from this obligation on a technicality.13
Hannibal chose not to march on Rome after Cannae. Both he and his army were utterly exhausted, for the battle had been long and hard fought under the heat of the summer sun. Hannibal himself had been very active throughout the battle, adding physical weariness to the mental stress of the days of manoeuvring and decision-making building up to the fighting. This probably contributed to his apparent lethargy, but the most probable reason for not moving instantly was his belief that this was unnecessary. Any other state in the classical world would surely have sought peace after a defeat on the scale of Cannae - probably just on its own and certainly in the wake of other serious defeats. War, as Hannibal had been raised to conceive of it and practise it, did not require the annihilation of the enemy, which was anyway seldom possible. Instead it required a demonstration that it was no longer in his interest to continue fighting. Once persuaded of this, a state or people conceded defeat and sought peace. This cultural assumption, more than anything else, probably explains why Hannibal did not move to threaten the city. In 216 BC the Romans did not obey Hellenistic conventions of war and accept defeat. Part of the reason why they continued to resist was the vast extent of the Republic's resources which allowed them to absorb the appalling casualties they had suffered. No other state had reserves of manpower on the same scale as Rome.
Even more important was the Romans' relentless attitude to war, which required every conflict to end in the absolute defeat either of the enemy or of themselves. It is possible that if Hannibal had moved directly on Rome after Cannae, the moral pressure exerted by the appearance of his army outside the city would have broken the Romans' spirit and ended the war. This may have been so, and with hindsight this was probably his best chance of victory. Yet such a move was also very dangerous and it is also possible that the Romans would have proved as stubborn as they did on other occasions, although none ever compared to such a threat. As with all the 'what if's’ of history, we can never know.