Deities from this region are depicted on the Pillar of the Boatmen.
Deities from this region are depicted on the Pillar of the Boatmen. This region was populated by several peoples who elected a chief magistrate called a vergobret as their leader. Marcus Postumus established a third-century empire named after this region, which was also the origin of Gaius Vindex's rebellion against Nero. The Arverni and Sequani tried to defeat the Aedui during a conflict in this region, which was home to the cities of Lutetia and Lugdunum. One leader who defeated Ariovistus at the Battle of Vosges in this region said that it was divided into three parts; that leader won a victory in this region at Alesia, thus subduing Vercingetorix. For 10 points, name this region roughly corresponding to modern-day France, the location of a war about which Julius Caesar penned some commentaries.
Deities from this region are depicted on the Pillar of the Boatmen.
Gaul [or Gallia; I guess you can prompt on France or Francia until "three parts"]