This denarius from the year 144 BC shows on its obverse the head of Roma, the personification of the city of Rome and the Roman state. She is wearing a winged helmet. Behind her is as indication of value the mark X for 10; the denarius was a 'tenner,' a silver coin worth 10 bronze asses.
The reverse shows Jupiter in a quadriga, a four-horse chariot. The godfather swings his scepter and is just about to throw a thunderbolt. Under the hooves of the galloping horses are the initials AN RVF, supposedly for the moneyer Titus Annius Rufus, and ROMA.
Jupiter with the thunderbolt is Jupiter Feretrius, the striker. Since time immemorial the Romans kept a flintstone in the temple of Jupiter Feretrius, that had been ground into a knife. Feretrius was called upon to witness solemn oaths, which were sworn 'per Iovem lapidem,' 'by Jupiter the stone.' An animal offering for the oath was killed with the stone knife, and breaking the oath meant punishment by Jupiter himself.