The altar coinage of Lugdunum

In 15 BC Augustus made Lugdunum (present-day Lyon), which opens at the meeting of the Rhône and the Saône, a mint of the empire. From 12 BC it became the centre for striking the gold and silver of the whole empire, and it held that place for about 50 years, until Nero returned the coinage to Rome. The design of the altar of the Three Gauls dedicated by Drusus was taken onto the coinage and circulated through the empire as a mark of the imperial cult and of the unity of Gaul. The gold of Gaul had become a medium for speaking of the emperor's power.