The Roman Amphitheatre at Martigny in the Valais

Martigny lies just north of the Great St Bernard Pass where the route meets the Rhone Valley flowing into Lake Leman.

In the 1st Century BC, Martigny was an oppidum of the Celtic Veragri tribe, called Octodurum. When Julius Caesar invaded Gaul, he sent Servius Galba with the XII Legion and cavalry to open the Great St Bernard Pass for Roman merchants, who had been charged large tolls by the local tribes. An example as so often of the flag (or in this case the eagle) following trade, rather than the other way round.

Galba after catering the local strongholds decided to over-winter at Octodurum. He fortified his camp with the usual bank and ditch. However he was suddenly attacked by the Gauls before the defences were complete. The battle lasted 6 hours and Caesar claims that 10,000 of the 30,000 Celts were slaughtered. After the Battle of Octodurum Galba withdrew into the territory of the Allobroges around Geneva where he wintered safely.

The local museum, probably with some justification, interprets this as Caesar being economical with the truth - perhaps it was a decidedly Pyrrhic victory if indeed it was a victory atall?

Nevertheless the region became part of the Roman Empire and in 47 AD the Emperor Claudius founded Forum Claudii Augusti which became prosperous as the first town after or before the Great Saint Bernard Pass. The map in the Gallo-Roman museum shows the road starting in Roma and ending in Londinuium!

The town prospered and acquired a large Forum and Baths, and of course the Amphitheatre pictured here. It's situation in a narrow Alpine Valley is clear from this picture.