This Roman denarius was struck in the year 49 BC somewhere on the campaign of Gnaeus Pompeius Magnus against Gaius Julius Caesar. In this Roman civil war both sides needed a lot of money to pay the troops.
The obverse depicts the Greek god Apollo.
The reverse shows the symbols of the Greek hero Hercules: an upright standing club with a lion's skin on top and a bow and an arrow on either side.
This design might have been chosen in anticipation of a victory of Pompey, whose epithet was Magnus, the Great. This was an allsion to no other than Alexander the Great, symbolized by Hercules and his lion's skin.