In the earliest times of Rome it was prohibited to represent the gods with human semblance. This attitude was at times reinforced as an action to determine the supremacy of the Roman gods.
This is of interest when we think of similar theological issues of “iconoclasm” regarding the representation of god and Christ which raged on right through the Renaissance and Baroque. We can see this theological problem making itself felt in Rome towards the end of the empire when mosaics of Byzantine inspiration avoided excessively naturalistic facial features in representations of holy figures.
There were also a number of gods according to human attributes such as Spes (hope) and Fides (faithfulness) for example. Relatively ad hoc gods also came into being such as “Romulus”, founder of the city, “Rome” the city itself and most if not all the city’s emperors from Augustus onwards. Julius Caesar was also deified after his death.
A face was given to all of these deities and they were often represented on coins and public buildings as part and parcel of the political propaganda of the times.
Each divinity had its easily recognisable, personal attributes such as lightning, eagles, a chariot, a cornucopia (horn full of fruit), a snake and so on. These attributes allowed the deities which might be represented on coins to be instantly recognisable and be associated with the ruler or emperor shown on the other face of the coin.