The Helvetii Invasion of Gaul, Caesar’s First Great Battle
“It was the traditional custom of the Helvetii to demand hostages of others, but never to give them – as the Romans had good cause to know.”1
Helvetii war chief Divico’s warning to Caesar
After its belated triumph over the Cimbri and Teutones menace, the venerable Roman Republic entered into its twilight century. Rome’s cold indifference to her Italian allies’ demands for equality provoked the Italian Wars (91–88 BC) which in turn set the stage for a series of civil wars. Gaius Marius, once hailed as the third founder of Rome, besieged Rome in 87. His seizure of the city was marked by a reign of terror. Marius’ men butchered Rome’s leading aristocracy in a bloody frenzy. The bodies of the victims were decapitated and the heads displayed in the Forum. After declaring his seventh consulship in 86 BC, Marius died of an illness at the age of 70. Revolts in northern Italy and in Spain led by Roman generals and the slave uprising of Spartacus (including survivors of the Cimbri wars) in the 70s further tore at the withering spine of the Republic.
Externally, Rome triumphed in Asia Minor over the formidable Mithridates, King of Pontus, cementing her hold over the Mediterranean. Italian military pensioners settled on provincial land grants. The city of Rome swelled to a population of around 750,000, 100,000 of which were slaves. The numerous poor lived in squalid tenements, kept satiated physically with a free grain ration and mentally with the chariot races and the slaughter of the gladiatorial and wild animal fights. Lavish villas and building projects reflected the vast wealth concentrated into the hands of the first multimillionaires. These urban-based real estate tycoons appropriated the choicest land at home and abroad. The workers who toiled on the land were a combination of free men and armies of slaves captured during Rome’s wars. Lesser family houses became the clientela of the greater ones. Corruption and violence in the streets became the order of the day.
It was in this period of political turmoil and in the beginning of the opulence and the grandeur of the future Imperial Rome that Gaius Julius Caesar became among the foremost politicians in Rome. Caesar’s prestigious family claimed descent from the founder of Alba Longa, one of earliest and legendary settlements of the Tiber valley. His aunt was the wife of Gaius Marius, a relationship which gained Caesar political clout as well as enemies.
Surviving prosecution by anti-Marian factions, Caesar rapidly climbed the Roman political ladder. He served as quaestor (financial magistrate), aedile (temple, street and grain supply administrator), Pontifex Maximus (chief priest of Rome) and praetor (justice magistrate) before attaining the consulship in 59 BC at 41 years of age. That year he masterminded the first Triumvirate between himself, the affluent Marcus Licinius Crassus and the brilliant general Gnaeus Pompeius Magnus. The Triumvirate all but dictated the Senate of the Republic. However, its members were uneasy allies. Each suspicious of the others, all three were caught in a deadly power play to retain or extend their political influence in Rome.
To compete with Pompey and Crassus, Caesar needed troops loyal to him and also needed military triumphs. Although he had led victorious, albeit minor campaigns, against the hill tribes and pirates of Spain, his primary battlefield had been the political arena of Rome. His military exploits paled in comparison to those of Pompey. Caesar’s chance came when the Helvetii appeared on the doorstep of Gallia Narbonensis, one of the three provinces, along with Gallia Cisalpina and Illyricum, of which Caesar currently was proconsul.
A Celtic people, the Helvetii originally hailed from southern Germany. Dislodged by Germanic tribes from the north, the Helvetii settled into the area of western Switzerland. But the German pressure did not cease so that in 61 BC the Helvetii towns and villages again stirred with talk of migration. One of their chiefs, the charismatic Orgetorix, proclaimed that all of Gaul would surely fall beneath the armed might of the Helvetii.
Orgetorix’s words were no mere boasts. Much of Gaul, especially the lands that bordered Roman Narbonensis and Cisalpina Gaul, had become semicivilized. Roman wine flowed north in exchange for raw materials and slaves. In the Gallic oppida, or fortified towns, pottery, glasswork and metallurgy flourished on an industrial scale. But the luxuries of civilization had softened the once barbaric Gauls. The Helvetii, by comparison, remained hardened due to their constant warfare with the Germans.
The Helvetii allotted themselves two years to gather provisions of wheat, draught-cattle and carts for the arduous journey. When the time came, in 58 BC, Orgetorix was no longer with them. Overly ambitious, he aspired to become king, although the Helvetii, like most of Gaul, had come to despise monarchies and were now governed by elected tribal magistrates. Put on trial, Orgetorix chose to commit suicide rather than risk the punishment of being burnt alive.
Orgetorix’s death did not dampen his peoples’ resolve to find greener lands elsewhere. Billowing smoke clouds rose behind lumbering caravans of wagons, livestock, horsemen and foot folk. In a testament to their determination never to return, the Helvetii set fire to their own fortress towns and hundreds of their villages.2 Their ultimate goal was the Atlantic coast and the fertile lands of the Santones.
The Helvetii would not be alone in their trek. Joining them were like-minded smaller tribes on the Helvetii border, the Rauraci, the Latobrigi and the Tulingi, and one of Rome’s most stubborn foes, the Boii. The Boii had been fighting Romans since 283 BC when they began a bitter struggle with Rome from their Cisalpina homelands. Eventually driven out of their lands by the Romans, the Boii drifted east to Bohemia and the Danube. Over a century later, large numbers of them struck westward again to meet up with the Helvetii.
The exact numbers of the Helvetii confederation will never be known. Caesar claimed they consisted of 386,000 men, women and children with a fighting strength of 92,000; surely an exaggeration. Given the primitive roads through Gaul and the relatively sparsely inhabited countryside, this number is impossibly high. It would have necessitated a marching column over a hundred miles long, one that would have been utterly incapable of supplying itself by forage in the surrounding countryside. Other numbers, both of classical and modern historians, vary widely from an acceptance of Caesar’s estimate to a mere fighting strength of 12,000 Helvetii warriors. The latter number seems too low, but it is doubtful that the Helvetii and their allies numbered over 90,000 people. Perhaps 25,000 would have been warriors, though not all in their prime years.3
The Helvetii could enter Gaul by the means of two routes. One way was the bridge across the Rhône at Geneva. Geneva dominated the lake outlet from a hill on the Rhône’s southern bank. Dating back to back to pre-Celtic Ligurian times, Geneva had been a settlement of the Allobroges for five centuries. Near the end of the second century BC, Geneva became part of the Roman province of Gallia Narbonensis. The other route, between the Jura range and the River Rhône, into Sequani lands was narrow and mountainous and easily defended by the Sequani and by the large forces of Germans who had settled there.
The Helvetii choose to face the Romans rather than the Sequani and Germans. They hoped that the Allobroges would revolt against their Roman masters. If they did not, the Helvetii would simply intimidate the Allobroges into allowing the migrants passage through the land. On 28 March 58 BC, the Helvetii assembled on the Rhône opposite Geneva but to their dismay found the Romans prepared for their arrival.
Caesar heard of the imminent Helvetii invasion while at Rome. To counter their formidable army, Caesar had but a single legion in Gallia Narbonensis. This was the Tenth Legion, which was destined to become the most famed legion in Roman history. By litter or chariot, taking naps while on the road, Caesar hastened to Geneva from Rome in a single week. He recruited what auxiliary troops he could and ordered the Tenth Legion to destroy the bridge over the Rhône. Caesar was turning out to be as energetic a commander as he had been a politician. The military life in the crisp clean air of the countryside, away from the cluttered streets of Rome, toughened his tall gaunt frame.
At Geneva, the destroyed bridge and the presence of Roman troops came as a rude surprise to the Helvetii. On 5 April they sent embassies to Caesar requesting a peaceful march through the province. Caesar had no intention of granting their request. Whatever the true intentions of the Helvetii, to feed themselves and their livestock, they would have to plunder the countryside they passed through. Caesar shrewdly delayed his answer till 13 April. He used the time to block the Rhône valley with 19 miles of fortifications including a trench and a 16-foot high wall.
When 13 April arrived, Caesar flatly denied the Helvetii entrance. Consequently, by day and by night, the Helvetii attempted to ford the Rhône in the river’s shallows. At other points they tied boats together to make crude rafts, but nowhere could they breach the Roman defenses. Although outnumbered, Caesar was able to rapidly concentrate his 6,000 troops at areas under attack. The Helvetii abandoned their plans to journey through Gallia Narbonensis. Instead they successfully appealed to the Sequani, and presumably their German overlords, to grant them safe passage through Sequani territory.
The new route took the Helvetii through free Celtic nations. Their ultimate destination, the lands of the Santones, was further away from the Romans than the original Helvetii homelands. The Helvetii migration was thus no longer of any concern to the Romans. Yet Caesar still coveted a decisive military confrontation. He preposterously declared that the Helvetii would end up dangerously close to the northwestern border of Gallia Narbonensis. To stop them, he left for Gallia Cisalpina leaving the Tenth Legion at Geneva under the command of legate Titus Labienus. In Gallia Cisalpina, Caesar enrolled two new legions and joined these with a further three stationed at Aquileia. In total, including Roman auxiliaries, this gave Caesar an army of over 30,000.
The Helvetii meanwhile had traveled through the Sequani territory. Probably because they were short on supplies, the Helvetii ravaged the Allobroges villages to the north of the Rhône and the Aedui lands on the Saône’s (the Arar) eastern bank. To the rescue of these tribes came Caesar with his legions.
Caesar’s journey was not without mishap. While taking the shortest route, the road from Ocelum across the Western Alps, his army was assailed by rebellious mountain tribes: the Ceutrones, Graioceli and Caturiges. Yet these minor tribes could do little more than harass the legions and were easily repulsed.
After crossing the River Isère, Caesar met up with Labienus and the Tenth Legion. At Lyon he received embassies from the Allobroges and the Aedui. They told him that the Helvetii were presently crossing the Saône River just north of the city.
At once Caesar set off towards the Saône. There his scouts reported that three quarters of the Helvetii coalition had already crossed the sluggish river. The section that remained was the bulk of the Tigurini, one of the four Helvetii cantons. Caesar was not about to miss an opportunity to catch a divided enemy. He sent Titus Labienus ahead with three veteran legions to hasten to the barbarian crossing. Labienus caught the Tigurini completely off guard. Heavily loaded with supplies and about to cross the river, the barbarians broke with barely a fight. Most were put to the sword while a few escaped into the nearby woods.4
Wasting little time Caesar had pontoon bridges constructed across the Saône, possibly with his three unengaged legions. The combined legions then set off in pursuit after the main Helvetii host, which headed north along the river. The Helvetii became alarmed at the speed of Caesar’s approach, for it had taken him a single day to cross the river while they, with their noncombatants, cumbersome wagons and livestock, had required twenty days. Helvetii deputies arrived at the Roman camp led by Divico, the grizzled Helvetii war chief, who forty-nine years ago annihilated a Roman army near Tolosa.
Divico stated that if left in peace the Helvetii would settle wherever Caesar should desire. However, if the Romans sought war then they should not let the defeat of the Tigurini lead to overconfidence. The Tigurini, after all, were caught unawares and away from their countrymen. He advised Caesar “to remember the earlier disaster of the Roman people [their defeat near Tolosa] and the ancient valor of the Helvetii.”5
Caesar was not about to be dictated by a barbarian. He replied that neither he nor the Roman people had forgotten their defeat by the Helvetii and the need for vengeance. If this were not reason enough to fight the Helvetii, then what of the atrocities inflicted upon Rome’s friends, the Aedui and Allobroges? In spite of these ample reasons to make war on the Helvetii, Caesar swore that he would still accept a peace. In return the Helvetii would deliver hostages to him and make full reparations to the Aedui and Allobroges.
In essence Caesar demanded that the Helvetii submit to Roman authority. As for the loot taken from the Aedui and Allobroges, much of it was taken to fulfil basic supply needs and would be impossible to return. Predictably, proud Divico answered that the Helvetii received but did not offer hostages, as the Romans well knew.
Divico returned to the Helvetii who continued northward. Caesar sent his entire 4,000-strong cavalry to monitor their movements. Caesar’s cavalry was made up of auxiliary troops drafted from the provinces, from the Aedui and from other allied tribes. Riding too close to the enemy, Caesar’s cavalry enticed the Helvetii into a combat. Boldly, 500 horsemen of the Helvetii rearguard rode to meet the enemy and fighting on favorable ground routed Caesar’s entire cavalry. Elated by their victory, the horsemen galloped on towards the main Roman army and skirmished around its perimeter. Caesar refused to give them battle and doggedly continued to follow the main Helvetii procession, which now moved westward and away from the Saône.
The commander who had begun the retreat of Caesar’s cavalry in the engagement above was Dumnorix, the leader of the Aedui contingent. As it turned out, Dumnorix was actually a Helvetii supporter. A foresighted individual, Dumnorix felt it was better to be conquered by other Celts than Romans. He correctly feared that the Romans were a threat to all of free Gaul. Clearly Dumnorix’s presence jeopardized the reliability of Caesar’s entire cavalry corps. However, because Dumnorix’s brother was Diviciacus, an influential and pro-Roman Chief of the Aedui and druid (high priest), Caesar could do little but keep a close eye on Dumnorix.
A fortnight later, the Roman scouts reported that the Helvetii had camped below a hillside. Caesar attempted to surround the enemy at night. The initial deployment went well. With two legions, Caesar crept around one flank of the Helvetii. Labienus with another two legions ascended the summit of a hill that overlooked the other barbarian flank. At dawn, a Roman scout commander from Caesar’s legions spotted Labienus’ legions holding the high ground on the hill. The commander mistakenly thought that Labienus’ legions were enemy troops and informed Caesar that the Helvetii held the hill. Due to this misinformation the attack was called off.
The Helvetii moved on, closely shadowed by Caesar. The next night the Romans camped near today’s Toulon-sur-Arroux, while only separated from the barbarians by a few miles. The following day Caesar decided to veer off toward Bibracte, the main Aedui town. His Gallic allies had failed to bring him promised supplies and he desperately needed to restock on wheat.
To the Helvetii it seemed that the confidence of the Romans was wavering. Perhaps they were aware of Caesar’s supply problems and wished to cut off their foes from Bibracte. The Helvetii now decided to give battle and caught up with the Romans in the valley of the Auzon Brook, around present day Amercy. They began to skirmish with the Roman rearguard but were temporarily checked by the Roman cavalry. Meanwhile Caesar drew up his four veteran legions in three echelons half way up the western slope of the valley. To his rear, on the ridge, he stationed the two newly enlisted legions and behind them the untrustworthy auxiliaries. To equalize the danger to all and prevent any thought of flight, he sent away his own horse and those of his lieutenants. Like common soldiers, the legati and the tribunes would fight on foot.
At the same time the Helvetii set up camp in the valley bottom, to the right of the Romans on the hillside. Leaving their women and children behind a barricade of wagons, the Celtic warriors assembled in a dense line. A feeble charge by the Roman cavalry was easily brushed aside. The Helvetii, Rauraci and Latobrigi led the attack. The Boii and Tulingi remained as a reserve in front of the wagon camp. Onward the barbarians marched until they faced the awaiting lines of Roman infantry on the hillside above.
Those legions presented a daunting sight for the motley barbarian horde. Drawn up in lines of centuries (usually 80 strong), maniples (two centuries) and cohorts (three maniples) the legion was the epitome of military discipline. They were armed to the teeth with the Spanish short sword (the gladius), two javelins (the pila), their oval laterally-curved shields, a bronze plumed helmet and a mail hauberk. Mounted on a standard, their silver Eagle, “the god of the legions,” soared above the men. The eagle was the physical embodiment of their strength and courage and served as a focal point for the lesser bronze animal standards of the cohorts.
The close-cropped and clean-cut legionaries were not only well armed and disciplined but also superbly drilled in the use of their weapons and kept fit through excruciating forced marches, running and swimming. On them hinged Caesar’s fate as a commander and his future in Rome. This would be his first major battle, one that would make or break his reputation. Fortunately for him, the odds were slightly in his favor. He had four veteran legions of 20,000 men who occupied the higher ground and together with his two green legions and auxiliaries enjoyed at least a marginal numerical superiority.
Compared to the enemy on the hill, the Celtic rank and file was poorly equipped. They had little protection other than wattle shields, although their chiefs sported bronze cuirasses and helmets adorned with extravagant horns or feathers. Many Celts fought stripped to the waist, in a show of true bravery and oneness with the elements of nature that figured so prominently in Celtic spirituality.
For the Helvetii the battle decided their future as a people. The warriors who faced the Romans knew that defeat would mean almost certain death or life long slavery, not only for themselves but also for their families.6 But the Helvetii had vanquished Rome’s legions before and they could do so again. The legionaries might have been drilled into the finest heavy infantry of the ancient world but they were still civilized men. In their hearts lurked a primeval fear of the tall and brawny barbarians who in the past had humbled Rome’s might.
In a huge disorderly phalanx the Helvetii, accompanied by wild shouts and boasts, moved uphill against their foes. A volley of javelins erupted from the Romans. The javelins tore into the Helvetii masses and stopped the barbarian advance cold. The din of the Roman trumpeters and horn blowers resounded along the Roman lines. With a shout, Caesar initiated the advance. He fought on foot, alongside his legionaries who drew their swords and charged. Many a barbarian faced them bare-bodied and unprotected, forced to cast away his javelin-pierced shield. Slowly the iron line of the Roman legions pressed back the barbarians, trampling the bodies of the fallen, across the Auzon and up the opposite side of the valley.
For a short while the battle calmed down as the exhausted barbarians retired further up the hillside. But now the fresh Boii and Tulingi surged at the exposed Roman right flank. Their attack revived the morale of their kinsmen on the hillside, who pressed forward with renewed vengeance. In a brilliant display of Roman discipline, the first two lines of the legions faced the oncoming main body while the third wheeled to engage the Boii and Tulingi.
The battle on the hillside was long and hard, lasting from noon until dusk. Urged on by their unforgiving and battle hardened centurions, the legionaries firmly held out against the barbarian wave that bore down the hillside. Fighting in line, with their short cut-and-thrust swords, two or even three Romans were able to engage a single barbarian, who needed more room to swing his longsword. When the legionaries in combat began to tire, fresh ranks from the rear would take their place. With such training and tactics, the legionaries slowly but surely forced the enemy back up the slope.
The Boii and Tulingi put up an equally tenacious fight. But like their brethren on the hillside, they could not breach the Roman lines and slowly battled their way back to the wagon camp. Here from behind the wagon barricades, the women and children joined the fray and hurled spears and darts upon the Romans. The cries and heroism of their women and children reinvigorated the Boii and Tulingi warriors who fought on with desperate courage. Not until midnight did the Romans take the last of the wagon ramparts.
When finally Celtic resistance broke on both fronts, less than half of them were left alive. The remainder withdrew from the battle but there was no panic-stricken rout. The survivors force-marched through the rest of the night, till three days later they reached the borders of the Lingones. They had left behind their wagons and belongings. No Roman followed them. The Romans were too busy healing their wounded and burying their dead who littered the valley, the hillsides, the brook and the destroyed wagon barricade. Amongst them lay some 40,000 dead Helvetii, men, women and children.
Caesar sent messages to the Lingones that they were to give no assistance to the Helvetii or face the wrath of Rome. Without supplies the Helvetii were soon reduced to misery. With tears in their eyes, these once proud people begged Caesar for peace. This Caesar granted, on his original demand of hostages and that the Helvetii turn in deserters, presumably from his auxiliaries, who had run over to the Helvetii. The bulk of the Helvetii agreed, with the exception of the Verbigene canton. Mistrustful of the Romans they made an unsuccessful dash for the German border. Caesar ordered the Gallic tribes that lay on the Verbigene path to the Rhine to catch the escapees. The hapless Verbigene were brought before Caesar who now treated them as enemies, which doubtlessly meant slavery.
Caesar was unusually generous to the remainder of the Helvetii. The Helvetii, Tulingi and Latobrigi were to return to their homelands and were to be provisioned by the Allobroges. There the Helvetii were to rebuild their burned homes. Caesar’s leniency was partially due to his fear that German tribes would occupy the empty Helvetii lands. It also increased his prestige among the Gauls. Remarkably, the Aedui petitioned Caesar to let the Boii contingent settle among them and this Caesar granted.
Caesar’s victory over the Helvetii was well received by the bulk of the Gallic tribes. Envoys arrived from all over Gaul, who wholeheartedly thanked Caesar for saving Gaul from the scourge of the Helvetii. Caesar claimed and widely publicized that he had destroyed nearly a quarter of a million of the enemy. To many a Gaul he appeared not as a conqueror but as their savior. Notably, he achieved this victory with only his four veteran legions. His two green legions and the auxiliaries remained in reserve during the entire battle, although their mere presence must have weighed on Helvetii morale.
When he had first received the proconsulship of Gallia Narbonensis and Gallia Cisalpina, Caesar by no means envisioned himself as a conqueror of all of Gaul. It was during his battles with the Helvetii, that Caesar’s shrewd opportunistic mind realized that Gaul was ripe for the taking. Beset with internal squabbles and external enemies, Gaul cried out for a savior and unifying force. His victory over the Helvetii put Caesar in a perfect position to become that savior and bring Gaul under Roman rule. Unconquerable in battle and a wise and just victor, Caesar won the respect and admiration of many Gallic tribes.
Yet the conquest of Gaul was anything but assured. Other tribes, especially those farther away from the Roman borders, would offer bitter resistance. Nor was Caesar the only one who desired the lands of Gaul. Soon after the Helvetii crisis, a delegation of Gallic chieftains led by Diviciacus pleaded with Caesar to deliver them from the tyranny of the German king Ariovistus.
While Caesar marched on to new martial glories, the Helvetii, as a free people faded from the limelight of history. Upon the remnant Helvetii Caesar bestowed the title “allies of the Roman people”. Roman colonies and subjugation soon followed. In time Rome pushed her frontiers north across the Alps to the Danube, absorbing the Helvetii, once among Rome’s staunchest foes, into her empire.