For his first trick as governor of Rome’s northern provinces, Julius Caesar will turn defense into offense and sow the seeds of conquest over Gaul.
During the Roman campaign against the war hawking Helvetii (Modern: Switzerland) in 58 B.C., Julius Caesar displayed notable tact and compassion in the face of his enemies. With an eye towards peaceful control of Rome’s frontiers, Caesar won his first military action as Proconsul in Gaul.
The Helvetii started on a warpath intent to conquer all of Gaul (modern: France, Belgium, Luxembourg, Switzerland, parts of Northern Italy, Germany, and the Netherlands). So set were they on this course that they in fact demolished their homesteads so as to inspire no consideration of failure by returning home. On March 28, 58 B.C, they reached the shores of Lake Geneva (Modern: Lake Geneva) where they were intercepted by Caesar who had torn down the bridge there to stop their passage into Rome’s provincial territories in Cisalpine Gaul, or Hither Gaul as Caesar oft referred, (Modern: Northern Italy–Southern France). They asked him to let them pass. Caesar bade them to return on April 13 so that he may consider their request.
In the meantime – a quite short time to do what I am about to tell you he did – he gathered five legions under his jurisdiction and built a wall sixteen feet high, nineteen miles long, and dug an entrenchment like a moat along it coursing with water drained from Lake Geneva where the Helvetii sought to cross. He never intended to actually consider their request. Based on past grievances against Rome and the warlike nature of the Helvetii, Caesar refused them passage.
The Helvetii tried to pass by boat, then by force, but were unsuccessful in doing anything but catching Roman arrows in their chests. So, they resolved to enter Gaul through the only other available route: a narrow mountain pass. To note, the Helvetii were considered a part of Gaul but were so situated in the Alps (Modern: Swiss Plateau), that they were effectively isolated from the rest of Gaul.
The Helvetii secured passage at this alternate mountain pass through the exchange of hostages and promises with the Sequani tribe (modern: Bourgogne-Franche-Comte, France). This negotiation was mediated by a powerful member of the Aedui tribe, Dumnorix, who will figure in importantly later on. So remember that he, Dumnorix of Aedui, gave favor to the invading Helvetii here.
Whereupon they passed the borders of the Sequani and entered near the borders of the Roman province (modern: Savoy), the Helvetii wreaked havoc on the tribes allied to Rome, enslaved children, captured towns and resources, and laid general waste to the land. Then, as the Helvetii crossed the Arar River (modern: Saone River) westward bound, delegates from the recently victimized tribes came to Caesar for help, among whom were the Allobroges and Aedui. In promise for his help, they offered food supplies and the company of their leaders to join Caesar’s camp as guarantees of cooperation, two of whom were Diviciacus, the king of the Aedui, and his younger brother, that Dumnorix. The reported damages bothered Caesar. Their ingratiating flatteries of Roman civilization and superiority persuaded Caesar. But Caesar had enough motivation to stop the Helvetii already. Around 107 BC, over thirty years earlier, the Helvetii handed Rome a humiliating defeat in the region resulting in the death of the Roman consul at the time and the great-grandfather of Julius Caesar’s wife.
So, Caesar set out after the Helvetii to avenge these sufferings. News came that three fourths of the Helvetii horde had just crossed the Arar River. One fourth of the Helvetii, specifically the Tigurine Helvetii, were yet to cross it. It had been these Tigurine who in fact put the embarrassing yoke of defeat over the Roman’s back in 107 B.C. Caesar quickly dispatched to light upon them and so caused a slaughter of that contingent. Thus, Caesar claimed revenge for Rome and family while weakening the Helvetii force.
Then, he ordered a bridge to be built across the Arar River, which had taken the Helvetii twenty days to cross by raft and swimming. The Romans’ bridge was built in one day. Remarkably astonished, the Helvetii immediately surrendered to Caesar. However, the Helvetii request for peace was delivered with a sarcasm insinuating that Caesar should accept this surrender for his own good or else he might suffer an embarrassing defeat like that his ancestors had there. Caesar displayed great restraint and presage by not reacting to the teasing, but rather accepted their surrender in exchange for hostages so to gain guarantee of their promised cooperation and subservience to Rome. The Helvetii leader, Divico, then refused acceptance of his own offered peace, egotistically asserting that the Helvetii only took hostages, never gave them. They then fled from Caesar and Caesar followed behind in pursuit. It was later determined that the Helvetii warforce consisted of 368,000 soldiers. Caesar in no way had more than 30,000 men at his disposable.
Unbeknownst to all but the Fates themselves, what occurred next between Caesar and the Helvetii would set the Republic of Rome on an historic path, the tract of which would leave an indelible mark on Europe and the rest of the world.