During the Roman Republic, nobilis ("noble," plural nobiles) was a descriptive term of social rank, usually indicating that a member of the family had achieved the consulship. Those who belonged to the hereditary patrician families were noble, but plebeians whose ancestors were consuls were also considered nobiles. The transition to nobilitas thus required the rise of a non-noble individual to the consulship, who was considered a "new man" (novus homo). Two of the most famous examples of these self-made "new men" were Gaius Marius, who held the consulship seven times, and Marcus Tullius Cicero.
The Second Samnite War (326–304 BC) was a formative time in the creation of this ruling elite comprising both patricians and plebeians who had risen to power. From the mid-4th century to the early 3rd century BC, several plebeian-patrician "tickets" for the consulship repeated joint terms, suggesting a deliberate political strategy of cooperation.
Scholarly attempts to define nobilitas have led to debates over the particulars of its usage in ancient sources. Fergus Millar points out that nobilis was a descriptive word as used in the Late Republic, and not a technical term for a restricted social group in the sense of peerage. Matthias Gelzer held that the term was reserved for descendants of consuls, and therefore reckoned that Munatius Plancus, consul designate for 42 BC, was the last man to qualify as an ancestor for a nobilis. P.A. Brunt, building on the view of Theodor Mommsen, assembled evidence of broader usage that suggests any curule office might grant the aura of nobilitas. The term is not found in the literature of the mid-Republic, and came into use long after the social and political changes that created "noble" plebeians.
During the time of Augustus, a nobilis enjoyed easier access to the consulship, with a lowered age requirement perhaps set at 32. Women who descended from Augustan consuls are also regarded as belonging to the Roman nobility. In the usage of Tacitus and Pliny Minor, a nobilis is a descendant of the Republican aristocracy. The meaning of nobilis then evolved during the Imperial period.
- E.T. Salmon, Samnium and the Samnites (Cambridge University Press, 1967), p. 217.
- Gary Forsythe, A Critical History of Early Rome: From Prehistory to the First Punic War (University of California Press, 2005), p. 269.
- Matthias Gelzer, Die Nobilität der römischen Republik (1912).
- Designated by Julius Caesar while dictator.
- Matthias Gelzer, in Hermes 50 (1915) 395ff., as noted by Syme, The Augustan Aristocracy p. 51, observing that "the notion was peculiar and vulnerable."
- P.A. Brunt, "Nobilitas and novitas," Journal of Roman Studies 72 (1982) 1–17.
- Fergus Millar, "The Political Character of the Classical Roman Republic, 200–151 B.C.," as reprinted in Rome, the Greek World, and the East (University of North Carolina Press, 2002), p. 126 online, originally published in Journal of Roman Studies 74 (1984) 1–19.
- Ronald Syme, The Augustan Aristocracy (Oxford University Press, 1989, 2nd ed.), pp. 50–52 online.
- Pliny, Panegyricus Traiani 69.5: illos ingentium virorum nepotes, illos posteros libertatis ("those grandsons of outsized men, those descendants of liberty").
- Barnes, T.D. "Who Were the Nobility of the Roman Empire?" Phoenix 28 (1974) 444–449. On usage of the term in the 4th century.
- Brunt, P.A. "Nobilitas and novitas." Journal of Roman Studies 72 (1982) 1–17.
- Hölkeskamp, Karl-J. "Conquest, Competition and Consensus: Roman Expansion in Italy and the Rise of the nobilitas." Historia: Zeitschrift für Alte Geschichte 42 (1993) 12–39.
- Ridley, R. T. "The Genesis of a Turning-Point: Gelzer's Nobilität." Historia: Zeitschrift für Alte Geschichte 35.4 (1986) 474-502.