Far removed are Geta and Caracalla from the greater (though imperfect) men, Romulus and Remus, brothers who founded Rome. The former are inheritors — and poor ones at that. This is not merely subtext.

Once upon a time, the goddess of love Venus seduced Anchises, a minor prince of Troy and second cousin once removed to King Priam. Nine months later, she presented him with the infant Aeneas and ...