When Caesar was in Gaul (57–56 BC) he sent Servius Galba with the Twelfth Legion and some cavalry to Gallia Transalpina, into the country of the Nantuates, Veragri, and Seduni.
Roman merchants could travel over the pass, but were sometimes attacked and were forced to pay tolls to the mountain tribes.
Galba, after taking many strong places, and receiving the submission of the people, sent two cohorts into the country of the Nantuates, and wintered with the remaining cohorts in a town of the Veragri named Octodurus, which was in a narrow valley, surrounded by mountains and divided by the Dranse river.
Smith mentions that due to the narrowness of the valley, the Gallic army might have been much smaller than Caesar's records and that the casualty figures might also have been inflated.
After burning the village, Galba marched out of the Alps and spent the rest of the winter in the lands of the Allobroges.