Caesar: Life of a Colossus

by Adrian Goldsworthy

  Caesar is unlikely to have known precisely how many migrants were waiting to cross the river into his province, but they certainly far outnumbered the single legion he had at his disposal. One of his first orders instructed the legionaries to break down the bridge crossing the river at Geneva. He also levied as many troops as he could find in the province, the tribes there providing him with contingents of cavalry. Soon after his arrival he was visited by a delegation of Helvetian leaders who asked permission for their people to move through the Roman province, promising that they would not plunder as they went. Caesar was unwilling to grant the request. In the Commentaries he takes this opportunity to remind his audience of a battle some fifty years earlier, when one of the clans of the Helvetii had defeated a Roman army. From a Roman viewpoint this had been an unprovoked attack, made worse when the survivors were forced to undergo the humiliation of passing under a yoke of spears, symbolising their loss of warrior status. This had been in 107 BC, in the midst of a series of disasters inflicted on Roman armies by the Cimbri and Teutones. Caesar wished to revive the fear of those years - something which was still just within living memory - amongst his Roman audience. They could then be reassured that Marius' nephew was there to defend them.

  Yet at the beginning Caesar did not have the means to do this. Instead he played for time, telling the Helvetian representatives that he would consider the matter, and inform them of his decision if they returned on the Ides - the 13th - of April, which was probably in one or two weeks time. During the interval he set the legion to constructing a line of defences running along the Roman bank of the Rhone from Lake Geneva to the edge of the Jura Mountains. It was the first of many engineering feats that his army would perform and was swiftly accomplished. For 19 Roman miles (each somewhat shorter than the modern mile at 1,618/ yards or 1.48 km) they raised an earth rampart some 16 feet high. This was strengthened at key points where the river could be forded by forts garrisoned by detachments of the legion and the other troops Caesar had raised. It is possible that the rampart was not absolutely continuous, having gaps whenever natural features ensured that it was impossible to cross, but there is insufficient evidence to confim this suggestion. Such a line was not a novel concept for a Roman army in this period. Crassus had made use of a similar fortified barrier in the campaign against Spartacus, and Pompey had done the same in the Mithridatic War. Such lines were practical, presenting an obstacle that would at the very least slow down an enemy, but also were a strong visible statement of intent and determination.9

  When the Helvetii returned for Caesar's decision, he bluntly informed them that `according to the custom and precedent of the Roman People, he could not permit anyone to journey through the province, and that he would stop them if they tried to force their way through'.10 The new fortifications were there to demonstrate that he meant what he said. However, it was difficult for such a great mass of people suddenly to change direction and purpose. The period of waiting by the river had also probably been very frustrating and many of the Helvetii were determined to keep going, especially after the years of preparation and the willing destruction of their old homes. Small groups began to cross the Rhone, either using the fords or rigging up rafts to carry themselves, their animals and vehicles. It is possible that these were deliberate probes sent by the chieftains to test the strength of Caesar's defences, but more likely that they reflected the loose central authority and individual independence that seems to have been characteristic of many of the tribes of Gaul. They were certainly not full-fledged assaults on the line of fortifications. Most of the crossings took place under cover of darkness, but a few parties were bold enough to risk the attempt in daylight. None succeeded, for Caesar's men were able to concentrate and meet each group in turn, overwhelming many of them with missiles as they struggled to cross. Eventually the Helvetii admitted defeat, but by this time some of their leaders had decided on another course, taking the alternative, more difficult route out of their lands. This meant taking the passes through the Jura Mountains into the lands of the Sequani. It would not have been practical if the latter had decided to resist them, but the tribe was persuaded by Dumnorix the Aeduan to let the Helvetii through. He was presumably able to do this through his own reputation and some of his many marriage connections with powerful men. Orgetorix was dead, but it would still be useful for Dumnorix to be able to call on the support of the powerful Helvetii once they were established in their own lands. Even before they began to lumber off in this new direction, Caesar received reports of their plans."

  ANEWWAR'

  It was probably at this point that Caesar finally resolved on a full campaign in Gaul against the Helvetii. The reason he gave in the Commentaries was that the Helvetii planned to settle `on the borders of the Santones, who lived not far away from the borders of the Tolosates, a tribe within the province. He understood that if this occurred, it would put the province in great danger, with many warriors, hostile to the Roman people, living close by a region which produced a rich harvest of grain, but was undefended.' His own recent actions had ensured the hostility of the Helvetii, but from a Roman standpoint his reasoning was sound. As we have seen, at the very least the incursion of the new settlers would have upset the existing balance system where a combination of Roman diplomacy and military strength had ensured the security of the province. Leaving his senior legate Labienus in charge of the defences on the Rhone - probably another indication that the Helvetii were travelling in lots of separate groups, and that it took time for such a sprawling mass of people, animals and vehicles to move off in a new direction - Caesar hastened to Aquileia and his main army. Two new legions, the Eleventh and Twelfth, were enrolled to add to the three already stationed there and the one left behind on the Rhone.

  The Commentaries give the impression that this was only done on Caesar's arrival, but the practicalities of recruitment and organisation make it more likely that he had already given the order for this some time before. The troops may originally have been intended to strengthen the army for operations in the Balkans, but the immediate threat of the Helvetii provided a better pretext for his audience. He had no authority to raise new legions, for only the Senate was supposed to instruct a governor to do this, but lack of specific power had never stopped Caesar in the past. As a youth and a private citizen he had raised allied troops to combat the pirates and oppose the Pontic invasion of Asia, while he had also raised ten cohorts - equivalent in numbers to a legion - during his term as propraetor in Spain. Never doubting that he knew what was in the interest of Rome and the provinces, Caesar simply acted and then trusted in his own ability to make things work. Since it had not authorised their existence, the Senate would not provide money from the Treasury to pay and supply the new legions, which meant that the proconsul would have to find the funds to do this from the revenue he raised in his province and any profits to come from victories. The bulk of the soldiers in the new formations were almost certainly from Cisalpine Gaul and so not actually Roman citizens and therefore legally ineligible for service in a legion. In the past Caesar had championed the desire of the population of the region for enfranchisement, and as governor he consistently treated them as if they were in fact citizens. This was the first major example of this deliberate policy.'2

  Soon, Caesar was ready to lead all five legions back to Transalpine Gaul. The quickest route was through the Alps, which although largely surrounded by Roman provinces was still unconquered. In a week the Roman column crossed the mountains, beating off successive ambushes from the fiercely independent tribes who resented this incursion and doubtless also saw the welcome opportunity for gaining some plunder. It was a harsh introduction to campaigning for the raw recruits, but the march seems to have been made without serious loss. Once over the mountains Caesar moved into the territory of the Allobroges, joining up with the troops he had left in the province. He now had six legions at his disposal, with a total of something like 25,000-30,000 men, and a force of allied cavalry that would soon
muster about 4,000 men, along with some light infantry. Added to this were the slaves who accompanied each legion to care for the baggage train, doubtless some also owned by the officers, and quite possibly also some camp followers. All of these needed to be fed, as did the thousands of cavalry mounts and draught and pack animals. Keeping his army supplied has always been one of the first concerns of any army commander. The operations against the Helvetii had developed so unexpectedly that Caesar had had little opportunity to prepare for this task by massing all that he needed in conveniently placed supply dumps in Transalpine Gaul. The main force is unlikely to have brought substantial supplies of food with it in its rapid march from Aquileia. It was still only spring, and the harvest would not become available for some months - Caesar notes in the Commentaries that it occurred late in these northern climes - so that the army could not expect to gather too much of what it needed from the land it marched through. Therefore messages went to Rome's allies, particularly the large and powerful Aedui, to gather stocks of grain and make them available for his troops.

  In the meantime the Helvetii had crossed through the Pas de l'Ecluse into the lands of the Sequani and were entering the borderland of the Aedui. Representatives of the tribe came to Caesar complaining of plundering attacks by the migrants. `The Aedui had always deserved well and that it is not right for our lands to be devastated, our children carried off into bondage, and our towns to be sacked almost under the eyes of a Roman army.' Similar complaints also came in from the Ambarri, a tribe allied to the Aedui, and the Allobroges, who had not that long before rebelled and been defeated. It is unknown whether or not the leaders of the Helvetii had consciously decided to launch these plundering attacks. Even if they had not, it would have been extremely difficult to control such a large and disparate group broken up into many individual parties. Given the delays imposed on their journey, some of the migrants may have been running short of supplies. Equally the hostility could have begun with the local peoples, nervous of the incursion of so many strangers. That violence resulted was unsurprising, but the need to defend or gain revenge for attacks on an ally was for the Romans a classic justification for aggressive warfare. It should also be said that this made practical sense. If Rome was unwilling or unable to guard its friends, then why should any tribe, especially the so recently discontented Allobroges, feel that it was worth maintaining the alliance? As consul, Caesar had passed a law regulating the behaviour of provincial governors and restricting their freedom to lead their army outside their province. In the Commentaries he demonstrated that it was entirely right for him to do just that.13

  Caesar caught up with the migrants near the Saone. For twenty days the tribesmen had been ferrying themselves across the river on rafts and small boats lashed together, and three-quarters of them were already on the far bank. It was another indication that we should not think of the Helvetii as moving in one ordered column, but in many separate groups spread over the landscape and only bunching when the path became narrow Still on the same side of the river as the Romans were the Tigurini, the clan that had been responsible for the humiliating defeat of the Romans in 107 BC. Caesar makes sure that he reminds his readers of this defeat once again, and adds that he had a personal stake in avenging it, since the grandfather of his father-inlaw Calpurnius Piso had died in the battle. After his scouts had reported this to Caesar, he decided on a surprise attack, leading his army out before dawn. The result was not a battle, but a massacre, as the Romans fell upon the scattered and unsuspecting groups of tribesmen and their families. Many were killed and the rest dispersed, abandoning their wagons and possessions. The Romans then bridged the Saone and crossed it in a single day.14

  As the Roman army closed with the rest of the Helvetii, their chieftains sent another delegation to the proconsul. To further emphasise the connection with 107 BC, Caesar claims that it was headed by the same man who had been their war-leader in that year, a certain Divico, who by this time must have been very elderly. The tribe offered to settle on whatever land Caesar suggested and promised to keep the peace with Rome. Yet they also showed that they were not dismayed by the surprise attack on the Tigurini, and warned the Romans not to despise their military strength, reminding them of the battle half a century before. They had learnt `from their parents and ancestors, to win battles through courage, not by guile or stealth'.15 A Roman audience would have seen this as dangerous pride which refused to acknowledge and submit to Roman might. Caesar told them that the defeat of Cassius' army in 107 Bc had only occurred because the Helvetii had attacked without warning, when they were not even at war with the Romans. Apart from this old wrong, he reminded them of their recent attacks on Rome's allies. He advised them against overconfidence, declaring that the immortal gods often granted short spells of success to criminals before they met with terrible punishment. (Caesar was Pontifex Maximus, yet this is one of very few references to the gods in his writings.) Only if they gave him hostages for their good behaviour and made restitution to the Aedui and others who had suffered from their depredations would he be willing to grant them peace. Retorting that the Helvetii `took, but never gave' hostages, Divico and his delegation stormed off. It is difficult to see how Caesar could reasonably have granted the request for land, since Gaul was already densely inhabited. He had no right to allocate them any territory outside his own province, and it would have been unthinkable to settle them inside. Wherever they went the Helvetii would inevitably cause disruption and this was not in the interest of the Romans.16

  The convoys of the Helvetii moved onwards, and Caesar followed them, sending his 4,000 cavalry out in advance. Amongst them was a sizeable force of Aedui led by Dumnorix, the same chieftain who had allied with Orgetorix and then aided the Helvetii. Advancing too carelessly, the allied cavalry were ambushed and beaten by a force of Helvetian cavalry a fraction of their size. The rout began with Dumnorix and the Aedui. Encouraged by this easy success, the enemy rearguard started to move more slowly and offered to fight more often. Caesar was unwilling to risk too many skirmishes with them, but kept the enemy under observation and stopped any parties from breaking away and plundering the landscape. His army followed the Helvetii, shadowing their every move so that his advance guard was never more than 5 or 6 miles from their rearguard. By this time he was some distance out of his province, and growing more worried about the supply situation. When he was near the Saone this had been less of a problem as he had been able to have food brought to him in the many barges plying this trade route. However, the Helvetii had moved away from the river, and so he had had to do the same. The Aedui had promised him grain - he was after all fighting against an enemy who had invaded and plundered their lands - but as yet nothing had arrived and repeated requests brought no results, in spite of frequent promises that it was on the way. In a few days time the soldiers were due to be issued with grain that Caesar did not at present possess. For short periods of time, soldiers on campaign have sometimes been persuaded to keep going on minimal rations, but usually only strong leadership made this possible. Caesar and his men were still relative strangers, while onethird of the army was very inexperienced.'

  Eager to avert a disaster, Caesar summoned the leading men of the Aedui, headed by the druid Diviciacus and Liscus, the man who currently held the post of Vergobret, the annually elected supreme magistrate of the tribe. Berated by Caesar over their failure to fulfil their obligations to an army that was fighting to protect them, Liscus blamed powerful men within the tribe who had deliberately held up the collection and transport of the grain, claiming that they thought it better to be dominated by their fellow Gauls the Helvetii, rather than the Romans. These chieftains were passing information to the enemy and intimidating anyone who dared to oppose them. Liscus had named no names, but Caesar was clearly already suspicious about Dumnorix and guessed that he was the man behind this. He dismissed the other chieftains and spoke privately with the Vergobret, who was now willing to talk more freely and readily confirmed the proconsul's suspi
cions. Dumnorix was aiming at kingship - coins dating to this period and carrying the name DUBNOREIX were probably minted by him - backed by a large force of warriors maintained with the profits from controlling the tolls on trade along the Saone. His complicity with the Helvetii was now fully revealed and Caesar felt that he had sufficient evidence to warrant stern punishment, but was hesitant since he valued the loyalty of Diviciacus. Therefore, he summoned the druid to an even more closed conference in his headquarters tent. He dismissed the interpreters he normally used and relied on Caius Valerius Procillus, an aristocrat from Transalpine Gaul whose father had won Roman citizenship for the family. Caesar, who had spent enough time in the courts at Rome, presented the facts and the case against Dumnorix, and suggested that either his brother or the Aedui needed to try him for these offences. Diviciacus told how his younger brother had depended on him for his success in public life, but had since turned against him as a rival. Some of Dumnorix's frustration is understandable, for the druid had recently held the office of Vergobret and the rule was that no other member of his family could win the post during his lifetime. Nevertheless, Diviciacus pleaded with Caesar not to punish his ambitious sibling, in part through affection, but mainly because he thought that it would be very damaging to him personally if he was seen to back the Romans against his own brother. His appeal was tearful and persistent. Dumnorix was summoned to the tent and in front of his brother presented with his crimes. The proconsul informed him that he was to be given another opportunity for the sake of his older brother, but that in future he must avoid even the hint of suspicion. Such faceto-face diplomacy was to be a common feature of Caesar's time in Gaul. As in Roman public life, much of what a governor did was at a very personal level. Caesar was famous at Rome for his readiness to forgive and his willingness to do favours. In Gaul he would sometimes follow the same principles. Yet nowhere was he ever naively trusting. After the meeting he gave orders that Dumnorix be kept under constant observation and everything he did reported to him.18