Narbo Marcius (Narbonne) was founded by Marius:  it soon became, according to Strabo and Diodorus Siculus, a place of very great trade.  The British tin, besides other articles, was brought by land-carriage through the centre of Gaul, and exported, either from it or Marseilles, to the different countries on the Mediterranean.  It derived great importance and wealth, from its being a convenient place of rest and refreshment for the Roman troops, as they passed from the Pyrennees to the Alps, or from the Alps to the Pyrennees.  Its harbour was crowded with ships from Africa, Spain, Italy, &c.; but, in the latter ages of the Roman Empire, it fell into decay, principally in consequence of the course of the river being changed, so that it no longer ran through it.  The Romans endeavoured to supply this misfortune, by cutting a canal to the sea, the traces and remains of which are still visible.

Lugdunum (Lyons), at the confluence of the Rhone and Arar, was founded by Manucius Plancus, after the death of Julius Caesar.  In the time of Augustus, according to Strabo, it had increased so much, by means of its commerce, that it was not inferior to any city in Gaul, except Narbonne.  Indeed, not long after the entire conquest of Gaul by the Romans, the advantages which that country might derive, with respect to foreign commerce, and internal trade, by its rivers, seem to have been fully and clearly understood.  The head of the Saone being near to that of the Moselle and the Seine, merchandize was easily conveyed by land from one of these rivers to the other.  The Rhone also received many goods by means of the rivers which joined it, which were conveyed, not only to the Saone, but also to the Loire, in carriages.  The Seine brought up goods almost as far as the Moselle, from which they were conveyed to the Rhine.  In the fourth year of Nero’s reign, the commander of the Roman army in Gaul joined the Saone and the Moselle by a canal; and, though these canals were generally made by the Romans, for purposes connected with the army, yet they were soon applied to commerce.  The merchandize of the Saone was brought by land carriage to the Seine, and by it conveyed to the ocean, and thence to Britain.  There seems to have been regular and established companies of watermen on these rivers, whose business it was to convey goods on them:  an ancient inscription at Lyons mentions Tauricius of Vannes, as the general overseer of the Gallic trade, the patron or head of the watermen on the Seine and Loire, and the regulator of weights, measures, and carriages; and other ancient inscriptions state, that the government of the watermen who navigated the Rhone and the Saone, was often bestowed on Roman knights.