Roman naming conventions are among the more counterintuitive aspects of the culture for modern readers, and the confusion they generate is not merely academic. Understanding Roman names is understanding something important about Roman identity, social structure, and the relationship between the individual and the family — a relationship that was organized very differently from the modern Western model.

The classical Roman name for a male citizen of the Republic consisted of three parts: the praenomen, the nomen, and the cognomen. The praenomen was the personal name — the equivalent of a first name — but it was used almost exclusively within the family. Romans did not address each other by praenomen in public contexts. There were very few praenomina in use — approximately eighteen were common, and many families used only two or three across generations — which meant that they were not functionally distinctive at any scale beyond the household. The praenomen was abbreviated in writing: Gaius became C., Marcus became M., Lucius became L. (confusingly, since Gaius was abbreviated C rather than G, a legacy of archaic Latin spelling).