In 25 BC, an army under Aulus Terentius Varro Murena wiped out the Salassi in the Aosta Valley. At some time between 25 and 7 BC - either following the Aosta campaign or, more likely, in the course of the conquest of Raetia in 15 BC - a campaign also subjugated the Celtic tribes of the Valais and opened the Great St Bernard Pass.