Cognomen

A cognomen (/kɒɡˈnoʊmən/,Latin: [koːŋˈnoːmen]; Latin plural cōgnōmina; con- "together with" and (g)nōmen "name") was the third name of a citizen of ancient Rome, under Roman naming conventions. Initially, it was a nickname, but it lost that purpose when it became hereditary. Hereditary cognomina were used to augment the second name (the family name, or clan name) in order to identify a particular branch within a family or family within a clan. The term has also taken on other contemporary meanings.

Because of the limited nature of the Latin praenomen, the cognomen developed to distinguish branches of the family from one another, and occasionally, to highlight an individual's achievement, typically in warfare. One example being Gnaeus Pompeius Magnus, whose cognomen Magnus was earned after his military victories under Sulla's dictatorship. The cognomen was a form of distinguishing people who made important feats, and those who already bore a cognomen were awarded another exclusive name, the agnomen. For example, Publius Cornelius Scipio received the agnomen Africanus after his victory over the Carthaginian general Hannibal at Zama, Africa (Africanus here means "of Africa" in the sense that his fame derives from Africa, rather than being born in Africa, which would have been Afer); and the same procedure occurred in the names of Quintus Caecilius Metellus Numidicus (conqueror of Numidia) and Quintus Caecilius Metellus Macedonicus.

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