The Via Domitia was the first Roman road built in Gaul, to link Italy and Hispania through Gallia Narbonensis, across what is now southern France. The route that the Romans regularised and paved was ancient when they set out to survey it, so old that it traces the mythic route travelled by Heracles. The construction of the road was commissioned by Gnaeus Domitius Ahenobarbus, whose name it bore, following the defeat of the Allobroges and Averni by himself and Quintus Fabius Maximus Allobrogicus. Gnaeus Domitius also established a fortified garrison at Narbo on the coast, near Hispania, to guard its construction. It soon developed into a full Roman colonyColonia Narbo Martius. The lands on the western part of the route, beyond the RiverRhône had been under the control of the Averni who, according to Strabo, had stretched their control to Narbo and the Pyrenees. Crossing the Alps by the easiest passage, the Col de Montgenèvre, it followed the valley of the Durance, crossed the Rhône at Beaucaire passed through Nîmes then followed the coastal plain along the Gulf of Lion. At Narbonne, it met the Via Aquitania. Thus Narbonne was a crucial strategic crossroads of the Via Domitia and the Via Aquitania, and it was an accessible, but well-defensible, port at that time. This "cusp point" in the Roman westwards expansion and ensuing supply, communication and fortification was a very important asset, and was treated as such. In between the cities that it linked, the Via Domitia was provided with a series of mansiones at distances of a day's journey for a loaded cart, at which shelter, provender and fresh horses could be obtained for travellers on official business. The route as it was in Late Antiquity is represented in schematic fashion on the Tabula Peutingeriana.
Route
This route can be traced on topographical maps overprinted with the ancient route, in G. Castellve, J.-B. Compsa, J. Kotarba and A. Pezin, eds. Voies romaines du Rhône à l'Èbre: Via Domitia et Via Augusta Paris 1997.
Narbonne At Narbonne, a section of the Via Domitia is exposed in the Place de l'Hôtel de Ville. The Via Domitia crossed the Atax by a seven-arched bridge at the site of the Pont des Marchands.