Denier with hippocampus facing left

The Allobroges occupied the territory between the Rhône and Isère rivers, a strategically critical corridor that Rome had controlled as the province of Gallia Transalpina since 121 BC. Despite being thoroughly within Roman administrative reach, the tribe continued striking their own silver coinage — a practice tolerated by Rome so long as local economies functioned and taxes flowed. The hippocampus type is one of the more distinctive Allobrogian issues, almost certainly influenced by Greek coastal coinage absorbed through trade networks running up the Rhône valley from Massalia.

The dating places this issue squarely within the years preceding Caesar's Gallic campaigns, when Allobrogian political loyalty was visibly unstable — the tribe had attempted revolt against Rome as recently as 61 BC.