In the 1st century BC, a Roman force advanced into Switzerland from Italy. We cannot yet be sure whether these soldiers were tasked with conquest, or mounting a punitive expedition to cow the inhabitants of the Alps. But we do know that members of this force were drawn from three different legions, and that they were making for a key Alpine pass. Ahead of them lay at least one battle. Over the last two decades, a remarkable range of finds associated with this incursion has been identified. In...