Cognomen

The cognomen (plural cognomina) formed one of the three parts of the typical Roman name. It followed the praenomen and nomen. Originally cognomina were nicknames, but by the time of the Roman Empire they were inherited from father to son. Thus the cognomen in combination with the nomen functioned as a surname, breaking families into smaller groups than just the nomen alone.

There were hundreds of cognomina in use. Some well-known examples are given in the following table.

Cognomen	Example
Brutus	senator Marcus Junius Brutus
Caesar	dictator Gaius Julius Caesar
Cicero	orator Marcus Tulius Cicero
Martialis	poet Marcus Valerius Martialis (Martial)
Nerva	emperor Marcus Cocceius Nerva
Scipio	general Publius Cornelius Scipio Africanus
Seneca	orator Lucius Annaeus Seneca
Tacitus	historian Publius Cornelius Tacitus
Valerianus	emperor Publius Licinius Valerianus (Valerian)