The princeps senatus (plural principes senatus) was the first member by precedence of the Roman Senate. Although officially out of the cursus honorum and possessing no imperium, this office conferred prestige on the senator holding it.
The princeps senatus was not a lifetime appointment. He was chosen by every new pair of censors (that is, every 5 years). Censors could, however, confirm a princeps senatus for a period of another 5 years. He was selected from patrician senators with consular rank, usually former censors. The successful candidate had to be a patrician with an impeccable political record, respected by his fellow senators.
The office was established around the year 275 BC. Originally, the position of the princeps was one of honor: he had the privilege of speaking first on the topic presented by the presiding magistrate. This gave the position great dignitas as it allowed the princeps to set the tone of the debate in the Senate. Across the 3rd and 2nd centuries BC, the office gained the prerogatives of the presiding magistrates and additional privileges, namely:
- Summoning and adjourning the Senate;
- Deciding its agenda;
- Deciding where the session should take place;
- Imposing order and other rules of the session;
- Meeting, in the name of the Senate, with embassies of foreign countries; and
- Writing, in the name of the Senate, letters and dispatches.
By 80 BC, it is believed that the status and function of the office was changed by the constitutional reforms of Lucius Cornelius Sulla. Although the term remained, reflecting the senator who was named first in the roll of the Senate issued by the Censors, the prerogatives of the office were restricted. In particular, the honor of speaking first on any topic debated in the Senate, a measure of their political clout, was removed from them and transported to the consul designate.
After the fall of the Roman Republic, the princeps senatus was the Roman Emperor, and during the period of the Principate, no other individual is believed to have held the office (see also: princeps). However, in the emperor's absence, it is possible that a Senator was granted the privilege of holding this role when the Senate met; the notoriously unreliable Historia Augusta claimed that during the Crisis of the Third Century, some others held the position; in particular, it stated that the future emperor Valerian held the office in 238, during the reigns of Maximinus Thrax and Gordian I, and he continued to hold it through to the reign of Decius. The same source also makes the same claim about Tacitus when the Senate acclaimed him emperor in AD 275.
List of known principes senatus
- Manius Valerius Maximus.
- Marcus Fabius Ambustus.
- c. 275/269 BC: Quintus Fabius Maximus Rullianus.
- c. 269/265 BC: Gaius Marcius Rutilus Censorinus?
- In or after 258 BC: Quintus Fabius Maximus Gurges, son of Rullianus
- c. 247/241 BC: Gnaeus Cornelius Blasio?
- c. 236/230 BC: Gaius Duilius?
- c. 225 BC: Manius Valerius Maximus Messalla?
- c. 220 BC: Aulus Manlius Torquatus Atticus?
- By 216 BC: Marcus Fabius Buteo.
- 209 – 203 BC: Quintus Fabius Maximus Verrucosus.
- 199 – 184/183 BC: Publius Cornelius Scipio Africanus.
- 184/183 – 180 BC: Lucius Valerius Flaccus.
- 179 – 153/152 BC: Marcus Aemilius Lepidus.
- 153/152 – c. 147 BC: Position vacant.
- c. 147 –141 BC: Publius Cornelius Scipio Nasica Corculum.
- Publius Cornelius Scipio Nasica Serapio?
- c. 136 – 130 BC?: Appius Claudius Pulcher.
- 130 BC?: Lucius Cornelius Lentulus Lupus.
- c. 125 BC: Publius Cornelius Lentulus.
- 115 – c. 89 BC: Marcus Aemilius Scaurus.
- By 86 BC: Lucius Valerius Flaccus.
- c. 70 BC: Mamercus Aemilius Lepidus Livianus.
- 62 - 60 BC?: Quintus Lutatius Catulus (Capitolinus).
- 55 - 44 BC:Publius Servilius Vatia Isauricus.
- 43 – 43 BC: Marcus Tullius Cicero. (Not a Patrician)
- 43 – 28 BC: Unknown.
- 28 BC – Augustus, title cohered with that of Roman emperor until beginning of the Dominate.
- AD 238 – 251: Valerian.
- AD 269: Pomponius Bassus - described as "Pomponius Bassus, who then was the first man".
- AD 275: Tacitus - The Historia Augusta states that Tacitus was "the consular whose right it was to speak his opinion first".
- Roberts, John (2007). "Princeps senatus". Oxford Dictionary of the Classical World. Oxford Reference. p. 858. doi:10.1093/acref/9780192801463.001.0001. ISBN 9780192801463.
- Ryan (1998), p. 170.
- Broughton, T. Robert S. (1952). The Magistrates of the Roman Republic. II. p. 127.
- Historia Augusta, The Three Gordians, 9.7; The Two Valerians, 5.4
- Historia Augusta, Tacitus, 4.1
- Mommsen, Willems, and Suolahti. Rejected by Ryan (1998), p. 223.
- Mommsen, Willems, Suolahti, and Ryan.
- Said also to have succeeded his father as princeps senatus in 265 BC.
- Willems, Suolahti, and Ryan.
- Willems. Rejected by Suolahti and Ryan.
- Mommsen. Rejected by Willems, Suolahti, and Ryan.
- Broughton, pg. 127
- Willems and Ryan. Rejected by Suolahti.
- Epitome de Caesaribus, 34.3
- Historia Augusta, Tacitus, 4.1
- Broughton, T. Robert S., The Magistrates of the Roman Republic, Vol II (1952).
- Mommsen, Theodor (1864). Römische Forschungen. I. and Mommsen, Theodor (1864). "Über den princeps senatus". RHM. 19: 455–457.
- Ryan, Francis X. (1998). Rank and Participation in the Republican Senate.
- Suolahti, Jaakko (1972). "Princeps senatus". Arctos. 7: 207–218.
- Willems, Pierre Gaspard Hubert (1878). Le Sénat de la République romaine. I.
- The Roman Law Library by Professor Yves Lassard and Alexandr Koptev.