There is an awful lot about this coin we don’t know. Let’s start with the obverse. It shows a figure seen from the rear, his drapery slipping from his muscular shoulder. He wears a diadem and has tousled, youthful hair. He wields, rather menacingly, an odd, spiralled shaft, with a forked and diverging spikes. This is how the Romans represented lightning. It’s no less realistic really than the odd zig-zag we tend to depict.
Essentially, the figure looks like he could be Apollo. But Apollo doesn’t hold lightning-bolts. That’s something that, with precious few exceptions, only Jupiter does. But Jupiter isn’t depicted as a youthful, beardless man. There is a youthful version of Jupiter, an obscure deity called Veiovis. But Ovid in Fasti 3 refers to Veiovis not having lightning yet; as the youthful Jupiter, he had not yet got hold of his iconic weapon. However, this should not really be an objection. Roman iconography is very happy with conflating scenes from later and earlier in the narrative, especially to make it clear who the deity is; without the lightning, we would immediately call him Apollo, for example.
The reverse of the coin shows at the top a bust of Vulcan and his tongs. The tongs may well be confirmatory symbolism again, though the hat is fairly clear in suggesting Vulcan. Crawford confesses that the meaning of this part is “not apparent” and that is true; he has quietly ignored Grueber’s endorsement of the idea that they refer to the office of the moneyer, as this is hardly convincing.
A.L. Frothingham, in a bold article called “Vediovis, the Volcanic God: A Reconstruction”, and published in the weighty American Journal of Philology 38:4 in 1917, attempts to shows that our Veiovis is an ancient deity of the lightning, earthquake, and general terran turmoil. Not all of the arguments are entirely convincing, but it would neatly explain the presence of Vulcan; we can then explain the Lares Praestites (which the ligatures must expand to) in their role as protectors against the ravages of fire. Perhaps. But this is all rather tenuous, and in danger of becoming circular. Scholars tend to have relief on each others’ tentative ideas in an area like this where we are so unsure, and this leads to unsure foundations. For example, Lott, in the excellent work The Neighborhoods of Rome (116) utilises the coin’s representation of Vulcan to link the Lares with protection from fire, but this is hardly secure.
I wonder how many of the ancient viewers “got” the imagery here? The iconography on the face of it hardly seems to be constructed for the masses. It clearly means something rather significant, but it is something allusive enough that we cannot grasp it – as yet. Perhaps however it was entirely transparent to the ancient viewers: it does seem a little arrogant to assume that because we don’t get it, they didn’t. Perhaps it was immediately significant to the people the moneyer cared about. In all humbleness, the family were not especially illustrious and this, the sole numismatic effort of the gens Caesia, may simply have been too obscure.
What I do know for certain, however, is that that is a fantastic dog. Perhaps it has venerable ancestors, iconographically speaking – it is shaggy in some of the same places as the Jennings Dog, for example – but in a coin as confusing as this, perhaps we should just enjoy the handsome dog for a while.