At the moment fear of a war in Gaul is the main topic of conversation [in Rome]; for “our brothers” the Aedui have just fought and lost a battle, and the Helvetii are without doubt armed for war and launching raids into our province.’ - Cicero, 15 March 60 BC.1

On 28 March 58 BC a people known as the Helvetii began to gather on the banks of the River Rhone near Lake Geneva. Some 368,000 people were said to be on the move, about a quarter of them men of fighting age, and the remainder women, children and the elderly. They wished to leave their homes in what is now Switzerland and cross to the western coast of Gaul, where they planned to settle on new, more extensive and fertile lands. Their route lead directly through the Roman province of Transalpine Gaul. News had reached caesar of the impending migration earlier in the month, and immediately prompted him to hasten to his province. Until then he had been waiting just outside Rome, keeping a close eye on the struggles in the Senate and in the Forum. The Helvetii wished to move through Transalpine Gaul, taking the easiest route to their destination. The northernmost frontier of Caesar’s great province was under threat, and public opinion would not be kind to a proconsul who dallied outside Rome while there was a crisis in the region placed under his command. After the chances he had taken to secure himself this command, Caesar could not afford failure of any kind. He hurried north, travelling with that phenomenal speed that so often amazed contemporaries. Covering on average 90 miles a day, he was on the Rhone eight days later. A crisis could also be an opportunity.2

The migration was not the result of a sudden impulse, but the outcome of years of planning. It had first been conceived by Orgetorix, described by Caesar as by far the ‘noblest and wealthiest’ man in the tribe, but he seems to have played upon existing frustrations. The Helvetii were a numerous and martial people who found their homeland increasingly restrictive, hemmed in by mountains, the Roman province beyond the Rhone, and the Rhine to the east. ‘With things as they were their freedom to range was restricted, and there were few opportunities of waging war on their neighbours; since they were men who craved war, they were greatly frustrated.’3 Raiding was endemic in Gaul, and it was the capacity to launch plundering forays with greater ease that the Helvetii desired. However, Caesar claims that Orgetorix had an ulterior motive, believing that uniting the tribe to this purpose would help him to make himself king. The Helvetii, like many of the other tribes, had ceased to be a monarchy and appear to have been ruled by a council of chieftains and by elected leaders or magistrates. Orgetorix had won over many other nobles and evidently possessed considerable power and support, for coins were minted at this time which carried his name in the form orciitirix. With the approval of the tribal leaders he was sent on a diplomatic mission to visit other tribes and prepare the way for the migration. Finding it easier to deal with individual chieftains rather than magistrates or tribal councils, he won over Casticus of the Sequani and Dumnorix of the Aedui. These two tribes dominated central Gaul, and the Helvetii would pass through or near their territory on the journey to the west. Their support, or even their non-intervention, would make the migration easier and help the Helvetii to establish themselves once they had arrived. Orgetorix encouraged both Casticus and Dumnorix to hope for supreme kingship in their own tribes, most likely promising them support from Helvetian warriors in the aftermath of the migration. Casticus’ father had in fact been sole ruler of the Sequani, and been formally acknowledged as a ‘friend of the Roman people’ by the Senate. Dumnorix was the younger brother of the druid Diviciacus, and had built up a considerable following in the tribe. The three leaders secretly took a solemn oath - always a sinister thing in Roman eyes - binding themselves to aid the others in their enterprises. Dumnorix also married the daughter of Orgetorix, continuing his fondness for marriage alliances - his mother had already been married off to the leading man amongst the Bituriges, his half-sister and other female relatives to various chieftains in the neighbouring tribes. Allied together, the three leaders of what would be the strongest tribes in central Gaul, felt that no one would be able to oppose them.4

The preparations of the Helvetii were thorough. Their leaders judged that at least two years - 60 and 59 BC - were needed to make themselves ready to move. Draught cattle were gathered, some apparently bought or taken from their neighbours, and the greatest amount of cereal crops planted to produce a surplus that would feed them on their journey Worrying reports of the plan came to the notice of the Senate in Rome, no doubt forwarded on by friendly leaders in the tribes as well as the governor of Transalpine Gaul. In 60 BC it was decided to send a delegation to Gaul, including a number of men with experience in the area and family connections amongst the tribes. Contact seems to have been made with the German King Ariovistus, who had been brought into Gaul to aid the Sequani against their rivals, but who had now settled with his warriors and their families on a large tract of tribal land. Otherwise we know little of the Roman delegation’s activities, but the situation did soon appear to be turning in Rome’s favour. In spite of the diplomatic success of Orgetorix, word reached the other Helvetian nobleman of his wider ambitions and he was placed on trial for aspiring to tyranny. The penalty for this crime was to be burned alive, and Orgetorix decided to intimidate the other leaders. On the day appointed for his trial he arrived accompanied by his warriors, dependants and all tribesmen bound to him by social obligation or debt, which gave him a force of over 10,000 men - perhaps an eighth of the entire military strength of the Helvetii. It was to be a contest between the budding institutions of a state and traditional patterns of aristocratic leadership. No actual trial could occur under such circumstances, but the other leaders were not permanently overawed and soon began to muster a full levy of the tribe with which to crush him once and for all. However, before civil war could actually break out, Orgetorix died amidst rumours of suicide. Preparations for the migration continued in spite of this, and his death did not in any way alter the tribe’s determination to go through with its plans. The Romans may not have fully appreciated that the momentum was still there even after the removal of the leader behind the plan. By May 60 BC Cicero felt that the prospect of a major war in Gaul had been averted, much to the displeasure of the consul Metellus Celer, who had been granted Transalpine Gaul as his province.5

This is Caesar’s explanation for the migration, a product of the tribe’s desire for greater opportunity to raid and the personal ambition of Orgetorix. Not all scholars have been willing to accept this at face value and have suggested that he concealed the truth in order to justify his own subsequent actions. They note, for instance, that the Commentaries make no mention of Ariovistus, the Germanic king who had fought for the Sequani and subsequently settled in their lands. This leads to the suggestion that the main intention of the Helvetii was to assist the other tribes in defeating Ariovistus and his Germans. In Caesar’s own consulship the German leader was named a ‘friend of the Roman people’ by the Senate and those fond of conspiracies suggest that he needed the neutrality or even complicity of Ariovistus to deal with the Helvetii in 58 BC. Once they had been defeated, he cynically turned on the German and drove him from Gaul. In this version, Caesar did not want the Helvetii to evict Ariovistus and so deny him the excuse for intervention in Gaul.6

None of this is convincing, for it is mainly reliant on hindsight. In the first place it is inherently unlikely that Caesar could have got away with such a massive distortion of the facts in his account, given that this was subject to hostile - and often informed - criticism. It is also unlikely that Rome would have viewed the expulsion of Ariovistus by the Helvetii entirely favourably. Their province of Transalpine Gaul was at present bordered by the Aedui and Sequani, both of whom had allied status. Ariovistus had recently been brought into the system. The province itself had just suffered a major rebellion on the part of the Allobroges and ideally required a period of stability if trade and revenue were not to suffer. The arrival of a strong tribe threatened to disturb this existing network of alliances. There was also the question of what would happen to the Helvetii’s own homeland once they left. If the abandoned land were then settled by newcomers, perhaps from one of the German tribes, then this might pose a new threat to the Roman province. On the whole the Romans were suspicious of the movements of peoples, so common in Iron Age Europe, and sought to prevent these from occurring in the lands near to their own provinces. Nor was it in their interest for the tribes of Gaul to unite independently of Rome.

Therefore Caesar would have had ample justification for intervention even if the Helvetii had intended to fight Ariovistus, and did not need to conceal this. On balance, his own account is far more plausible. Casticus and Dumnorix clearly both believed that they would gain from the arrival of the migrants, and doubtless expected support from Orgetorix against all their opponents, whether foreign or within their own tribe. Those leaders of the Sequani who had invited Ariovistus into Gaul in the first place, and the many chieftains who would appeal to Caesar for aid over the coming years, acted with the same motives. Association with a strong external force boosted a chieftain’s prestige, and might well be converted into direct military assistance. It is misleading to speak of pro- or anti-Roman factions within the tribes - or for that matter pro- or anti-German or Helvetian groups. Each individual leader sought whatever aid he believed would be of most benefit to him, and all were engaged in the struggle for dominance within the tribe. Some leaders, and indeed the ruling councils of some tribes, decided that they were better off allied to Caesar and Rome, while other men and peoples who were their rivals acted differently.7

Yet in the spring of 58 BC there is every sign that Caesar was wrong-footed by the Helvetii. Perhaps he had been surprised by the timing of the migration, or maybe its sheer scale. He had four legions at his command, but only one of these was in Transalpine Gaul. The remaining three were camped near Aquileia on the border of Cisalpine Gaul nearest to Illyricum. It is not known who stationed the troops there, but even if it had not been Caesar, then he had made no effort to alter this disposition. Even when he hastened to the Rhone he made no effort to send new orders to these troops. It is hard to avoid the conclusion that he was still thinking very much in terms of a Balkan campaign. Perhaps it was only when he arrived near Geneva that he appreciated the full scale of the problem. The Helvetii and the allied clans who joined them in the migration had piled their possessions into wagons and set off with great purpose. Behind them they left the smouldering ruins of their towns and villages, deliberately put to the torch to discourage anyone from wavering if the journey became difficult. Caesar may have exaggerated when he claimed that every single settlement was burned, and indeed in the implication that not a single tribesman remained behind, but the upheaval was clearly a massive one.

The figure of 368,000 migrants was said by Caesar to have been taken from captured records that the Helvetii themselves had made using Greek characters - Gallo-Greek inscriptions using the Celtic language but Greek alphabet are fairly common finds from southern Gaul and attest to the long presence and influence of Massilia. Any numbers found in an ancient text must always be treated with a degree of caution, since it is so easy for them to become distorted over the centuries as manuscripts were copied and recopied. In cases of this sort, the Roman desire to quantify military victory in the numbers of enemies killed and cities captured encouraged deliberate exaggeration. It is certainly a very high figure, suggesting a density of population considerably higher than would be expected, even in a region so overcrowded as to produce a migration. Yet in the end we know so little about ancient levels of population that it is unwise to be too dogmatic, and if we reject Caesar’s figure then we have nothing with which to replace it. Modern suggestions of more ‘plausible’ totals can never be anything more than conjectural. In the end, even if Caesar did exaggerate, or was genuinely mistaken, a substantial number of people and animals were on the move, probably in many separate parties rather than one immensely long column, which would have presented huge practical and logistical problems. However, at certain points, such as river crossings and mountain passes, there would have been a tendency for the different groups to cluster closer to each other.8

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 1,61814 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.11


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.12

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 one- third of the army was very inexperienced.17

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 suspicions. 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 face- to-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

Although the hindrance to the grain supply had been removed, it was not an instant solution to his problems, and it would still take time for the Aedui to bring the grain to his army. Caesar needed to force a quick outcome to the campaign, and on the same day as he had held these meetings he believed that he had spotted the opportunity. His scouting patrols came back to report that the Helvetii had camped some 8 Roman miles away, next to some high ground. Caesar sent out another patrol to carry out a detailed reconnaissance of the position, looking in particular at how readily the slopes of the hill might be climbed from each side, especially that furthest from the enemy. This party returned to report that the ascent was straightforward. Caesar decided to launch a full-scale attack on the enemy camp, hoping to achieve the same sort of surprise he had gained against the Tigurini. Labienus was given command of two legions - persumably two of the experienced ones - and would march out in the small hours of the morning to seize the hill. Two hours later Caesar would lead out the rest of the army and march the 8 miles to the enemy camp. When Labienus saw him beginning his assault, he was to attack with his legion from the high ground. Both forces were to follow the same route for most of the way, being guided by men who had taken part in the previous day’s patrol and seen the ground in daylight.

It was a bold plan, but a perfectly feasible one, using a method of preparation that in its essence would not be unfamiliar to a modern army Caesar had plenty of experience of raids and surprise attacks, rather more than he had of pitched battles, for warfare in the Spanish Peninsula tended to be of this type. Marius had similarly managed to secrete a strong detachment of men in dead ground behind the Teutones at Aquae Sextiae in 102 BC. Operations at night have always been risky, for the potential for confusion and units getting lost is always there. In this case things began very smoothly Labienus moved out and disappeared into the darkness. After the appointed interval Caesar followed with the main force. The cavalry led the column, and sent out patrols to screen the advance. These scouts were placed under the command of one Publius Considius, an experienced officer with a fine military reputation. He had served under Sulla and Crassus and was therefore probably at least in his forties. Caesar does not give his rank but he was probably a tribune or prefect, although it has sometimes been suggested that he was a centurion. It is possible that he was a relation of the senator Considius, who the year before had declared that, unlike many others, he was too old to worry about danger (see p.177).19

By dawn the main force was only a mile and a half from the enemy camp, and Labienus was waiting in position, but was out of contact with Caesar. The Helvetii, like many tribal armies somewhat careless in scouting, were completely oblivious to the presence of either force. At this point Considius galloped in to report that the hill was not in fact held by the Romans, but by the Gauls. He was absolutely positive about this, saying that he had clearly seen their weaponry, crests and insignia. The news meant that Labienus had either got lost and never reached his destination or that he had been defeated. In either case the Helvetii were obviously well prepared and waiting for them. Caesar immediately halted the column. He had four legions, two of which were most likely the raw Eleventh and Twelfth. His men were also tired after the night march, still doubtless fresh enough to attack surprised and scattered opponents encumbered by baggage and families, but not necessarily up to a long drawn-out pitched battle. To attack under these circumstances would have meant fighting at a serious numerical disadvantage on ground chosen by the enemy He ordered the column to withdraw to a nearby ridge and there formed them into a battle line to await any attack. Time passed. The Helvetii roused themselves and set off to continue their journey, still completely unaware that the shadowing Roman army had now come so close and had divided. Labienus followed his orders to the letter, not engaging until he saw Caesar’s men beginning their attack. In any case, there was little that he could have done with just two legions at his disposal. It was only late in the day that scouts from the main force established contact with Labienus’ detachment and confirmed that they, and not the enemy, held the key position. In what was left of the day Caesar took the army after the Helvetii, setting camp that night 3 miles away from them.20

It had been an embarrassing failure, but could so easily have proved disastrous if the Helvetii had fully appreciated the situation and turned on either section of the Roman army. Labienus’ men had been especially vulnerable on the hill. Caesar had learned that he could trust the judgement and sense of his senior legate, but not that of other officers, however great their reputation. It was a lesson in the risks inherent in complex operations and the role in warfare played by chance. Caesar makes no mention of whether or not he punished Considius for losing his head, but the publication of the Commentaries ensured that his shame was widely known. In his account Caesar passed the blame for the failure onto his subordinate. This was not entirely unreasonable, but his soldiers may not have seen it that way at the time. Caesar had given the orders, and it was he who had halted the main force on a false report and taken a very long time before checking its accuracy. During this period their comrades in the two legions with Labienus had been left very much out on a limb. The pursuit of the Helvetii continued, but the situation was not good. The wheat ration was due for issue in two days, but there were no supplies for this. On the following morning Caesar decided that things could not continue as they were and gave orders to abandon their cautious chase of the Helvetii for the moment. The army turned away and marched to Bibracte, some 18 miles away He planned to replenish his supplies there and then move against the Helvetii once more. Given the latter’s plodding progress, it should not prove too difficult to catch up with them again.21

With hindsight this proved the turning point in the campaign. Some warriors serving amongst Caesar’s Gaulish allies quickly deserted and rode over to the enemy, reporting the Roman withdrawal. The Helvetii decided to pursue, presumably interpreting the move as a sign of weakness. Caesar also wondered if they hoped to cut him off from Bibracte and his supplies. The Roman rearguard was soon under attack. Caesar reinforced it with all of his cavalry and used them to cover the deployment of his army Occupying a nearby hill, he placed the experienced Seventh, Eighth, Ninth and Tenth legions in the main line. If he followed his later practice, then the Tenth was probably in the place of honour on the right of the line. Each legion was deployed in the normal formation, the triple line (triplex acies) with four cohorts in the front line, and three each in the second and third. The legionaries laid down their packs - normally carried suspended from a staff that was then rested on the shoulder - so that they could fight unencumbered. Shields were removed from their protective leather covers to expose the insignia of each unit, and crests fixed to helmets. Behind them, further up the slope, he stationed the inexperienced Eleventh and Twelfth legions along with his auxiliary infantry. They were to guard the packs and the baggage train, and began to dig out a small trench and rampart to surround them, but it is very unlikely that there was time to construct a fully fledged marching camp of the type normally built by any Roman army at the end of a day’s march. It was important for the soldiers in the battle line to know that their possessions were safe, and clearly Caesar was still reluctant to trust these inexperienced soldiers. Probably the four experienced legions formed a line covering most of the slope, but as with most of Caesar’s battles it has proved impossible to locate the site of this encounter, so that we cannot talk about the topography with any certainty. Caesar does tell us that the slope ensured that the two legions and the auxiliaries were clearly visible to the enemy, covering the hillside in men and creating a strong impression of the Romans’ numerical strength.

The deployment of the army took time - probably several hours - and was covered by the cavalry, but the Helvetii also needed a good deal of time to advance and prepare themselves for battle. They had been travelling for some weeks now, and had through necessity developed a degree of coordination, but even so it was a major task concentrating enough of their warriors in one place to overcome the Romans. With the fighting men came their families and dependants, along with the baggage, and the Helvetii formed the wagons into a rough laager behind their line. Gradually their army began to form up, but the fighting would begin before some contingents had arrived. Caesar does not supply any figure for the number of warriors he faced at the start of the battle, but the willingness of the Helvetii to attack would suggest that the two sides had at the very least a rough parity of numbers - that is unless the tribesmen were utterly disdainful of the Romans’ fighting prowess. Long delays before a battle were common in this period, which inevitably must have been a nervous time as men had little to do save wait. Caesar decided that a grand gesture was called for and very openly dismounted and sent his own horse to the rear, along with those of all his senior officers, in order to ‘make the danger equal for all, and remove the temptation of flight’. Catiline had done the same thing in 62 BC before the battle when his outnumbered followers had been cornered by an army loyal to the Senate. The gladiator Spartacus had gone a step further in his last battle, slitting the throat of the expensive horse he had captured from a Roman general in an earlier encounter. A general on foot was a lot less mobile and therefore could see less of the battle as it developed, so Caesar had sacrificed a number of practical advantages to encourage the men in this way. He would never again do this in any of his later battles, and it does suggest that he was aware that his legionaries did not yet know him that well, and that the campaign had not been going especially well in the last few days. Perhaps it was also an indication that he was not yet entirely sure of himself as a commander. For further encouragement he addressed the men, probably walking along and talking to each cohort in turn since it is unlikely that all four legions could have heard him at the same time.22

Battle of Bibracte

The battle began in the middle of the afternoon, when the Helvetii advanced up the slope against the Roman line. They came on in good order, keeping a close formation. Armies tried to intimidate their opponents before they reached them, frightening them with their battle cries, the noise of their trumpets and their ferocious appearance. It was not uncommon for one side to be so overawed that they would break and flee before ever a blow had been struck. This was one of the main reasons why it would have been risky to expose the recently raised legions to the pressure of battle. In this case, the experienced legionaries waited, their normal tactic in this period was to keep silent, intimidating the enemy by their apparent calmness. When the Helvetii came close - probably within 10-15 yards - the legions threw their pila, the heavy javelins punching through shields and in some cases even pinning two overlapping shields together. Some warriors were killed or wounded, others forced to drop their encumbered shields. The momentum had gone from the attack and the Romans followed up their advantage by cheering, drawing their swords and then charging into contact. They had the advantage of ground and the enthusiasm and impetus of the charge, but even so the Helvetii fought on for some time before they began to give way and retreated down into the plain. The Romans followed, but seem to have done so in an orderly manner and soon lost contact with the fugitives, who ran back to the high ground on the other side of the valley, about a mile away. However, at this point the Romans faced a new threat, as a fresh contingent of 15,000 warriors arrived on their open right flank. These were the Boii and the Tulingi, two allied peoples who had been further back in the Helvetian column. It is unlikely that this was a planned manoeuvre and that the first attack had been no more than a feint to draw the Romans down onto the level ground - it was probably just a happy coincidence for the Helvetii. A tribal army - even a Hellenistic army where the doctrine was to mass the infantry in a single dense line without significant reserves - would have been in serious trouble in this situation, in danger of its whole line being rolled up by the fresh enemy. In contrast the Roman military system emphasised the importance of a reserve, normally keeping at least two- thirds of their force back from the fighting line at the start of a battle. The third line of cohorts was peeled away and formed into a new line to face the Boii and Tulingi. The first and second lines dealt with the Helvetii, who had rallied at the appearance of their allies and returned to the fray. The Eleventh and Twelfth do not seem to have been brought up from the extra reserve Caesar had in this battle and appear to have remained mere observers of the action.23

The battle was hard-fought and continued until well after nightfall, but after the initial shock of the arrival of these new forces, the Romans made steady headway. The struggle for the wagon laager was especially bitter, as the warriors fought to defend their possessions and families. Caesar makes no mention in his account of what he did during the battle, it is simply ‘the Romans’ who wheeled and formed fighting lines facing in two directions. Presumably he was doing what every Roman commander should do, staying close behind the fighting line, encouraging the men and committing reserve troops as necessary. In the end the victory was complete, but the Roman losses were comparatively heavy and the army was to remain where it was for three days to look after the wounded and bury the dead. Numbers of prisoners had been taken, including both a son and daughter of Orgetorix, but Caesar says that 130,000 people escaped from the battle and fled north east towards the territory of the Lingones. In the circumstances it must have been hard for him to make an accurate count, but clearly sizeable numbers of the migrants survived the battle. Many may not have reached it at all, but those who had been involved had lost most of the baggage. Caesar did not pursue immediately. He had still not sorted out his supply situation, and the care he showed for his casualties was important in adding to the growing trust between army and commander. Instead he sent messages to the chieftains of the Lingones, ordering them not to aid the Helvetii, unless they wanted to be treated as enemies.

After three days he set out after the enemy, but was soon met by a delegation offering to surrender. Caesar instructed them to tell the tribesmen to halt and wait for him to reach them and give a decision. That they did so was an indication that they were not simply playing for time. When Caesar arrived he demanded and received hostages, as well as getting the Helvetii to return the slaves who had fled to or been taken by them during their migration. The warriors were also disarmed. On the first night some 6.000 men from one clan broke away from the camp, heading eastwards towards the Rhine. Caesar sent messengers to the communities in their path with the same stark warning as he had given to the Lingones. The fugitives were brought back and sold into slavery, being denied the terms that he extended to everyone else. The Helvetii and most of their allies were then ordered to return to their homelands and settle there once more. Instructions were sent to the Allobroges in his province to supply the returning tribes with grain until they had re-established themselves once more, rebuilding their burnt settlements and cultivating their farms again. After an appeal from the Aedui, Caesar allowed them to settle the Boii on lands within their tribal territory. Stability was restored to the lands surrounding Transalpine Gaul, but the cost in human lives had been very high. In conclusion, Caesar states that of the 368,000 people listed in the records captured from the Helvetii, only some 110,000 returned home; the 32.000 Boii - minus their casualties from the battle - settled in Gaul, while 6.000 fugitives were sold into slavery, leaving a massive deficit of 220,000. As always we cannot know how accurate these figures were, and presumably very large numbers of people had simply dispersed in the face of Roman attacks, just as the Tigurini had done at the Saone. Nevertheless, many - perhaps tens of thousands - must have been killed, but we should not let the modern horror at such huge loss of life blind us to the response of Caesar’s Roman audience to such statistics. For them, a dangerous movement of hostile peoples had been stopped and their province, which was not far from Italy itself, secured for the future. In the Commentaries Caesar often makes use of the verb parcere which meant ‘to pacify’ and was used for the defeat of any people, anywhere, who had refused when challenged to submit to Roman authority Pax or ‘peace’ was the outcome of a Roman victory. From the Roman perspective, peace had returned to the northern frontier.24


By this time it was summer. Several months of the campaigning season remained, but there would not have been enough time to shift the forces back to the Balkan frontier and begin operations there. Caesar had already won a great victory, but was hungry for more and reluctant to stand idle even for a short time. He was soon presented with an opportunity for a further military adventure. Delegations had come in from most of the Gallic/Celtic tribes of central Gaul congratulating him on his defeat of the Helvetii. The praise may in part have been genuine, but it was obviously wise to establish good relations with any new power that had moved into the region. These envoys requested permission to summon a meeting of all the tribes at which they could meet him and present petitions. In another tearful scene, chieftains threw themselves at the proconsul’s feet and, with the druid Diviciacus as their spokesman, begged Caesar to protect them from the German King Ariovistus. They claimed that the man who had been invited in to aid the Sequani had since then brought in and settled 120,000 of his people on their lands and taken hostages from all the tribes. They complained of his tyranny, calling him a ‘wild, uncontrolled barbarian’. More Germans were said to be coming to join their war-leader and Caesar was asked ‘to defend the whole of Gaul from the onslaught of Ariovistus’. Representatives from the Sequani silently supported the plea, Diviciacus answering Caesar’s enquiry by saying that they were too afraid to speak lest word be carried to the Germans. Caesar then assured the gathered chieftains that he would take care of the matter and use his auctoritas to persuade Ariovistus to moderate his behaviour. Privately he took the matter very seriously, feeling that he must support the Aedui because of their long and loyal alliance with Rome. Apart from that, he also claims that he was concerned about the Germans getting into the habit of migrating across the Rhine, lest this happen too frequently and cause folk movements on the scale of the migrations of the Cimbri and Teutones.25

Envoys were sent to Ariovistus asking him to meet with Caesar at some point midway between them. The king declined, saying that Caesar must come to him if he wanted to talk, and also asking why the Roman felt he needed to intervene in this part of Gaul. In response Caesar sent a new message, reminding the king of the obligation he ought to feel because during his own consulship the Roman people had acknowledged him as ‘king and friend’. This time the demands were clearly expressed. Ariovistus was not to bring any more Germans across the Rhine to settle in Gaul. Secondly, he must restore the hostages to the Aedui and refrain in future from raiding or threatening them. Compliance would ensure continued good relations with Rome, but refusal would force Caesar to take firm steps to safeguard the Aedui and other allies of the Republic. Ariovistus’ reply showed a similar unwillingness to compromise. He was a conqueror and, just like the Romans, saw no reason to be dictated to by others in his treatment of the conquered. The Romans were free to run their provinces as they wished and he claimed the same right in the lands he and his warriors had taken. He had beaten the Aedui, and their hostages had nothing to fear from him as long as the tribe delivered their annual tribute to him. He and his warriors had never been defeated since they came to Gaul and feared no enemy Having established Ariovistus’ overweening pride to his audience, Caesar claims that within an hour of receiving this message, envoys came from the Aedui reporting that their lands had been raided by the Germans. In addition, the Treveri from further north sent word that huge numbers of Seubi - the Germanic people to which Ariovistus and his men belonged - were at the Rhine and trying to cross into Gaul. There were supposed to be one hundred clans making this attempt, a migration that would have dwarfed that of the Helvetii.26

Caesar decided to act, but this time made sure that his grain supply was secure before he began to move. He drove the army on at a quick pace, for they were no longer following the sluggish Helvetii, and after three days received a message informing him that Ariovistus and the German army were advancing on Vesontio (modern Besancon), the main town of the Sequani. Clearly by this time the tribe had broken with its former ally. As the tribal centre it was an important place, sited in a naturally strong position and with large food stores that would be very useful for any army. Not willing for this to fall into enemy hands Caesar drove his men on, forcemarching both day and night with only brief rests until he reached the town, into which he put a garrison. With the race won, he gave the troops several days of rest to recover from their exertions, and also to allow his supplies to catch up. Discontent has always tended to flourish more when armies have time on their hands, rather than when they are busy. Rumours were rife in the town and:

a panic spread after conversations with the Gauls and the traders, who said that the Germans were a race of huge stature, incredible courage and skill with weapons - they claimed that often when they met them they had not been able to sustain even their glance and keen expressions. Then very suddenly a great panic seized the entire army, dismaying the minds and spirits of all ranks. The thing started with the military tribunes and prefects, and the rest of the men lacking military experience who had followed Caesar from the City in an effort to win his friendship: some put forward some excuse obliging them to depart, others asked permission to leave, and a few were shamed into staying ... they were unable to conceal their depression, or at times hide their tears; they cowered in their tents to bemoan their fates, or gathered with friends to lament the common danger. Throughout the entire camp men started drawing up their wills. With these voices of despair, even men with long experience of campaigning, soldiers, centurions, and cavalry officers were affected.27

Some men claimed that they were more worried about the difficult terrain through which the army would have to pass in the next stage of the advance. Others said that they were nervous about the grain supply - a plausible enough concern in the light of the recent operations against the Helvetii. A few officers even declared that there would be an open mutiny and that the soldiers would not obey Caesar’s order to advance. The episode provides another indication that the fanatical loyalty which Caesar’s officers and soldiers displayed in later campaigns, especially during the Civil War, did not spring up instantly on Caesar’s arrival in Gaul, but took time to grow. It is interesting that Caesar portrayed the tribunes and other officers as the source of the discontent, for these men were usually equestrians and often the sons of senators. This reinforces the view that these classes were not the sole, nor even necessarily the main target audience for the Commentaries. Dio claims that some of these men complained that the war against Ariovistus had not been authorised by the Senate, so that they were risking their lives purely because of Caesar’s personal ambition.28

The proconsul summoned a consilium (a council or briefing). All of the centurions - some 360 men if all of these posts were filled in the six legions - were instructed to attend, along presumably with the other senior officers. It was time for Caesar the orator to use reason and charm his army as he had often in the past worked a crowd in the Forum. He began sternly, as befitted a general given imperium by the Senate and People of Rome, and told them off for daring to question the plans of their legally appointed commander. After giving them this shock and reminder of discipline, Caesar switched to argument. Their nervousness might well prove unnecessary, since there was every chance that Ariovistus would remember his obligation to Caesar because of his recognition by Rome in the previous year and see reason.

Even if fighting became necessary, Roman legions had met and defeated German warriors in the past, when Marius smashed the Cimbri and Teutones, and more recently when there were many Germans amongst the slave army of Spartacus. Ariovistus had beaten the Aedui and other Gauls by outwitting and surprising them, not in a fair fight. Such crude strategems would not work against a Roman army. Those who openly worried about the grain supply insulted him by doubting his care and competence, while ignoring the convoys already coming from allied tribes and the ripe harvest now visible in the fields. He was not worried by the claim that his soldiers would refuse an order to advance:

... at any time when an army has not listened to its commander, either fortune has failed them or bad mistake been discovered . . .. My own integrity has been shown in my life, and my good luck in the war against the Helvetii. Therefore I intend to carry out what I had planned to postpone till a later date, and to break camp in the fourth watch of this coming night, so that I may see once and for all if duty and honour prevails in your hearts over fear. Anyway, even if no one else follows, I shall set out with just the Tenth Legion, for I have no doubt of its loyalty, and it will act as if it were my own guard.

Caesar had favoured this legion, and had the greatest confidence in its courage.29

The whole speech was a challenge to the centurions’ pride in themselves and their units. Caesar’s tone displayed disappointment in them, since only cowardice and lack of faith in his leadership could explain their threatened refusal to obey orders. The Tenth was flattered, and its tribunes immediately reported the legion’s readiness to obey Caesar’s every order and prove that his trust was not misplaced. The other units were each determined not to be outshone by any other legion, and their centurions asked the tribunes and senior officers to assure Caesar that there had never been any real question of disobedience.30

As he had promised, Caesar marched the army out of camp before dawn of the next day. He did change his plans in one way, which may suggest that he had seen some justification in a little of the criticism. Rather than continue as he had originally planned, through the hills, he sought advice from Diviciacus and took the column through open country This meant a detour of 50 miles, but prevented a fresh outbreak of croaking amongst his officers. After a week, his scouts reported that the German army was only 24 miles away. Envoys soon arrived from Ariovistus, saying that he was now willing to have the face-to-face meeting that he had previously declined. In the Commentaries Caesar claims that he still hoped for a peaceful resolution of the problem, and this may not simply have been intended to emphasise his reasonableness to his audience. Many Roman commanders, Sulla included, had celebrated the occasions when, surrounded by the full pomp and ceremony of a Roman magistrate and surrounded by the serried ranks of the legions, they had confronted a foreign king and dictated terms to him. There was almost as much glory in such a deed as there was in defeating the enemy in battle, although the potential profits were less, with no prospect of plunder or slaves.31

Five days later the meeting took place on the neutral ground of a plain roughly equal in distance between the two camps. Only one large mound interrupted the flat land. The details of how this would take place had been hammered out in long negotiations during the preceding days. Ariovistus insisted that each of them should only have horsemen in his entourage. Not fully trusting his allied horsemen, Caesar borrowed their mounts and gave them to legionaries from the Tenth so that these provided his escort. Once again delighted to be singled out from the entire army, the soldiers joked that the proconsul was making them knights (equites), punning on the ancient role of the wealthy equestrian order. The two parties stopped 200 paces apart. In accordance with Ariovistus’ wishes, each leader then rode forward with only ten men as escort. The language used was Gallic, which Ariovistus had learned during his time west of the Rhine. Caesar presumably used one of his usual interpreters. He began by reminding Ariovistus of the favour done to him by the Republic and the obligations that this implied. The Aedui were very long-standing allies of Rome, and the German’s treatment of them was unacceptable and must stop. Caesar’s demands were the same as before. No more Germans must be allowed across the Rhine into Gaul and the Aedui must have their hostages returned. Ariovistus’ attitude had not changed. What he had won, he had won through right of conquest. Why was Caesar interfering in a place where no Roman army had ever ventured before? This was his ‘province’, just as Transalpine Gaul was Caesar’s, and neither of them should interfere in the other man’s territory. The German wondered whether ‘despite Caesar’s pretence of friendship, he had brought the army into Gaul to destroy him’. Until the Romans withdrew, Ariovistus would treat them as enemies. In the Commentaries he makes the barbed comment that if he killed Caesar, the news would be welcomed by ‘many of the principal men and nobles’ back in Rome. This may well have been true, but none of his opponents would have liked to be depicted as men so lacking in patriotism that they would be pleased by the defeat of a Roman army as long as it meant Caesar’s death. Having made the threat, Ariovistus then offered to support Caesar in every future operation if he withdrew now.32

Caesar responded with more justification of the Roman position, but the parley broke up when some of the German warriors began throwing javelins or slinging stones at the mounted legionaries. He decided against fighting, since he did not wish to give the impression that the Romans had broken faith. After two days, Ariovistus sent word asking for another meeting, or alternatively for the Romans to send envoys to his camp. Reluctant to risk any of his senior officers on this mission, Caesar again showed his trust in Valerius Procillus by selecting him for the task. With him went Caius Mettius, a merchant who in the past had visited Ariovistus and received his hospitality. This time the welcome was less warm and both envoys were denounced as spies and thrown into chains by the Germans.33

Ariovistus had evidently decided on a military solution to the dispute. Yet he was an experienced war-leader who had welded his warriors into a more cohesive force than most tribal armies and he still acted cautiously On the same day as he arrested the Roman envoys, he advanced to camp on high ground 6 miles from the Roman position. Probably remaining on high ground, he led his army out again on the following morning and marched past Caesar’s camp to establish a new base 2 miles behind the Romans. This cut Caesar off from his supply lines to the allied tribes. For five days the proconsul ordered his army out of camp and formed a battle line. The Germans refused to come down and Caesar clearly felt it unwise to risk a direct attack on Ariovistus’ camp, which suggests that it was in a strong position. There were skirmishes on these days, mostly between the cavalry, but no full-scale fighting developed. Ariovistus’ horsemen worked closely with picked light infantry - who in later centuries were known to the Germans as the ‘hundred’ (centeni) - capable over short distances of keeping pace with the horses by grabbing onto their manes. The warriors on foot acted as a solid support, behind which the cavalry could retreat if worsted, and rest and re-form before advancing again. The tactics and the quality of the Germanic warriors usually gave them the edge over Gaulish cavalry.34

Caesar could not afford to remain where he was, for he was achieving nothing and each day his army consumed a significant part of the supplies he had with him. A direct attack was too risky, so instead he decided to reopen his supply lines. The army formed into three columns, each of which could be readily converted into a fighting line to make up the normal triplex acies. The baggage train and presumably some guards remained in the main camp, for Caesar only intended to create an outpost beyond the German position. The Romans marched past the German camp to a spot just under 1,000 yards away from it. Once there the legions faced towards the enemy. The German cavalry along with 16,000 infantry came out to oppose them. This was only a part of Ariovistus’ foot, but it is unlikely that he was able to get more of them armed and ready for battle quickly enough to intervene. Caesar ordered the cohorts in the third line to begin laying out and constructing a new camp to accommodate two legions, while the first and second lines met any German attack. These probably took the form more of probes and feints rather than an all-out assault. If most of the six legions took part in this manoeuvre then two-thirds of their strength plus the cavalry and light troops would at the very least have matched the German numbers. After several hours of this, the camp defences were ready. Two legions were installed, while the rest of the army marched back in the same order to the main camp. The smaller fort would now make it easier to protect supply convoys coming from the allied tribes. The pressure on Caesar for a quick victory or an ignominious retreat was removed, and he could afford to wait for the moment and situation of his choice before engaging the enemy army.35

On the next day Caesar ordered the legions out of both camps to form up in the standard triplex acies facing the enemy. It was a gesture of confidence, intended to encourage his own men and impress the enemy, and he says that this was his normal practice during these days. Ariovistus declined the offer of battle and at noon the Roman commander sent his men back. Later in the afternoon the Germans did become aggressive, sending out troops to attack the smaller camp, but the troops there were able to repulse the onslaught. That evening Caesar personally questioned some of the prisoners who had been taken. These men claimed that Ariovistus was reluctant to risk a full-scale battle because the women who acted as diviners for the German army had declared that he would only win a victory if he waited until the full moon. Ceremonies and sacrifices were normal in most armies before battles, but Caesar, the Pontifex Maximus, makes no mention throughout the Commentaries of the rituals that were a very important aspect of the legions’ routine. In this case, he decided to exploit the superstition of the enemy. On the next day he stripped the camps of all but the barest minimum of guards and formed the rest of the army into a triplex acies, with the cavalry probably on the wings. He then led the army straight up the slope against the Germans, going far closer to their camp than he had ever done on the previous days. This challenge was too bold to ignore without humiliation, and the risk that his warriors would become daunted by the enemy. Ariovistus led out his men, who formed in units according to their clans and tribes - mention is made of seven distinct contingents. Behind the line were the warriors’ wives, perched on wagons and cheering on their men folk, begging them to protect them from slavery at the hands of the enemy.36

Battle against Ariovistus

In this battle all six legions took their place in the battle line, so that Caesar clearly felt that the Eleventh and Twelfth now had sufficient experience of campaigning to cope with the stress of battle. Probably they were both sandwiched between more experienced units and it is very likely that a veteran legion was stationed on each flank. Caesar’s five legates and his quaestor were each given command of a legion ‘so that every man should have a witness of his courage’. He stationed himself on the right flank, where he thought the enemy line was weakest and most likely to be broken. The battle began suddenly, both sides charging into contact without the normal exchange of missiles. Caesar managed to break through the enemy left, but was too closely involved to keep much control of the other sectors of the battle. The German right began to drive back the Roman left, and it was only the prompt action of the young Publius Crassus, who as commander of the cavalry ‘could move around more easily than the officers in the main line’, which saved the day. Crassus ordered up the cohorts of the third line and they restored the situation. Soon afterwards the breakthrough on the far wing spread panic throughout the entire German army, which collapsed into flight. Caesar himself led his cavalry at the head of a pursuit that was both determined and utterly ruthless. One later source that probably refers to this battle claims that he deliberately gave an escape route to a group of Germans who were desperately resisting so that he could slaughter them more easily in flight. Ariovistus himself escaped, and from then on disappears from history Two of his wives - one the sister of a Norican king - and one of his daughters were less fortunate and were killed amidst the general massacre. Another daughter was captured. Even some of those fugitives who escaped across the Rhine were then attacked by other tribes. The Seubi, who were supposed to have been waiting to join their kinsmen in Gaul, returned to their own homes. Much to Caesar’s delight, the troops he was actually with came across Valerius Procillus and were able to rescue him from his captors. The proconsul claimed that the reunion gave him ‘as much pleasure as the victory itself’. The emotion was surely genuine, though of course it also helped to confirm Caesar’s reputation for loyalty to his friends. Procillus was doubtless even more relived, for he told them that the Germans had three times asked the diviners whether he should be burnt to death, but that thrice he had been saved by the lot. The other captured envoy, the trader Mettius, was also released unharmed.37

The campaigning season was at an end and Caesar had completed - in his own words - ‘two very great wars in a single summer’. Neither had probably been anticipated by him before his arrival in the province, but he had seized the opportunities offered to him. For the moment at least his attention had switched to Gaul and would remain there in the immediate future. Caesar spent much of the winter in Cisalpine Gaul, carrying out the administrative and judicial tasks required of a Roman governor, and also keeping an eye on Rome. His army remained and went into winter quarters in the territory of the Sequani. Come the spring they would be ready for further operations deeper into Gaul.38

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