Bordering directly on Italy, control of the province gave the Roman state several advantages, such as control of the land route between Italy and the Iberian peninsula; a buffer against attacks on Italy by tribes from Gaul; and control of the lucrative trade routes of the Rhone valley, over which commercial goods flowed between Gaul and the trading center of Massalia.
It became a province in 121 BC, originally under the name of Gallia Transalpina. The Romans called it Provincia Nostra ("our province") or simply Provincia ("the province"), a name which has survived in the modern name of the region, Provence.
The name Gallia Narbonensis stems from the Roman colony of Narbo Martius (Narbonne) which was founded on the coast in 118 BC
Gallia (in English Gaul) is the Latin name for the region of western Europe occupied by present-day France, Belgium, western Switzerland and the parts of the Netherlands and Germany on the west bank of the Rhine river.
Besides the Gauls of modern-day France, Gauls had settled in the plains of northern Italy, in the province Romans knew as Gallia Cisalpina ("Gaul this side of the Alps") and Venetia et Istria.
The area was subsequently governed as a number of provinces, the principal ones being Gallia Narbonensis, Gallia Lugdunensis, Gallia Aquitania and Gallia Belgica.
It was bounded on the west by the Atlantic Ocean, on the south by the Pyrenees Mountains and the Mediterranean Sea, on the north by the English Channel, and on the east by the Alps and the Rhine.
Gallia Cisalpina, or “Gaul this side of the Alps” as viewed from Rome, was also called Gallia Citerior, or Hither Gaul, to distinguish it from Gallia Ulterior, or Farther Gaul, better known as GalliaTransalpina, or “Gaul across the Alps”.
Many illustrious Romans were born in the territory of Gallia Cisalpina, including the poets Virgil and Gaius Valerius Catullus, the historian Livy, and the statesmen and writers Pliny the Elder and Pliny the Younger.