This silver denarius was struck in the years 48-47 BC in a mobile military mint. It was a time of war for the Roman Empire, and coins had to be minted where they were needed. The issuer was Julius Caesar, who used such coins to pay for the wages of his soldiers, and for self-promotion.
The obverse depicts Pietas, the goddess of duty towards gods, parents, siblings and relatives, but also towards the state and the fatherland.
The reverse shows a trophy draped with Gallic arms and booties: a horned helmet, a tunic, a shield and a carnyx (a Celtic wind instrument). The axe surmounted by an animal's head next to it is a sacrificial axe, used by Roman priests to kill sacrificial animals. The design of the coin celebrates Caesar's victories in the Gallic wars of the years 58 to 50 BC.