Battle of Arar

The Battle of Arar (58 BCE) was the first battle fought during the Gallic Wars (58-51 BCE) between Julius Caesar and the Helvetii.

On the 28th March 58 BCE, the Helvetii burnt their villages and towns, so that they had to migrate.
Julius Caesar was determined to stop the migration of the Helveti into Gaul.
Caesar had the bridge at Geneva, territory of the Roman Client Tribe the Allobriges, destroyed to prevent them crossing.
Caesar had fortified the river bank with a 16 foot (5m) Rampart and Trench, Ballistas, Archers, Slingers and Remi Cavalry, to back up the Legion.

Caesar had to bring his five Legions from Italy, and had to fight to get through a Pass in the Alps to reach the Helvetii.
When he arrived three-quarters of the Helvetii had already crossed the River Arar.

Three Legions, commanded by Caesar, then engaged the Tigurine (a Helvetic sub-Tribe) who were still crossing the river.
The Legions annihilated the Tigurine caught in the river, and drove the rest into the woods.

Although Caesar didn’t prevent the Helvetii crossing, he caught and wiped out a quarter of their number.
The Romans built a bridge over the River Saone, and pursued the remaining Helvetii for two weeks before Caesar started running out of supplies from his Allies, which were possibly delayed as part of the Helvetii tactics.
Caesar sent 4,000 cavalry to pursue the remaining Helvetii, to give him time to get supplies. These however, were met and stopped by a unit of 500 Helvetic Cavalry.
Julius Caesar then recalled his Cavalry and moved the Legions into the town of Bibracte to await supplies from his Allies and consolidate against the impending Helvetii attack.
At this point the Helvetii turned back and pursued the Romans, leading to the Battle of Bibracte.