The curio maximus was an obscure priesthood in ancient Rome that had oversight of the curiae, groups of citizens loosely affiliated within what was originally a tribe. Each curia was led by a curio, who was admitted only after the age of 50 and held his office for life. The curiones were required to be in good health and without physical defect, and could not hold any other civil or military office; the pool of willing candidates was thus neither large nor eager. In the early Republic, the curio maximus was always a patrician, and officiated as the senior interrex. The earliest curio maximus identified as such is Servius Sulpicius (consul 500 BC), who held the office in 463. The first plebeian to hold the office was elected in 209 BC.
The election of a plebeian to succeed an impeccably pedigreed Aemilius Papus was predictably controversial, even though the office of curio maximus had become "anachronistic and somewhat bizarre", and the election of both a plebeian pontifex maximus as early as 254 BC and rex sacrorum just the previous year would have seemed to clear the way. When the patricians objected to the candidacy of Gaius Mamilius Atellus, the tribunes of the plebs, who normally withheld themselves from religious affairs, were called in. They followed procedure by referring the matter to the Senate, who promptly tossed it back to them. Political jockeying no longer discernible in the historical record was perhaps in play. Mamilius was duly elected, and held the office until he died of plague in 175 BC. His successor, also a plebeian, was Gaius Scribonius Curio, whose new cognomen passed to his descendants, most notably the father and son active at the time of Julius Caesar.
The electoral procedure for the office of curio maximus probably resembled that of pontifex maximus; that is, election through the tribes. Others known to have held the office include C. Calvisius Sabinus, the consul of 39 BC.
The curio maximus presided over the Quirinalia, and also the agricultural festivals of the curiae such as the Fordicidia, when pregnant cows were sacrificed, and the Fornacalia, or Oven Festival. The Fornacalia had no fixed date, and though each curia might celebrate the festival separately, the date was determined by the curio maximus and posted in the forum. Although the curio was a kind of priest, he had the power to convene meetings for political purposes, and each curia also had a flamen curialis whose duties were specifically religious. Another duty of the curio maximus was collecting "religious contributions" from the curiae (curionium aes).
- Festus refers to "the maximus curio, by whose authority the curiae and all the curiones are ruled" (maximus curio, cuius auctoritate curiae, omnesque curiones reguntur, p. 113L).
- Betty Rose Nagle translates curio maximus as "chief warden," taking curia in the sense of ward, in her translation of Ovid's Fasti (Indiana University Press, 1995), p. 202, note 6 online.
- Rachel Feig Vishnia, State, Society, and Popular Leaders in Mid-Republican Rome, 241–167 B.C. (Routledge, 1996), p. 105 online. This restriction was evidently relaxed by the late 30s BC, when Calvisius held the office.
- The interreges held elections when the consuls were unable to. The senior or first interrex did not actually preside over the elections, though it was theoretically possible for him to do so, and since the interrex was required to be a patrician, this technicality may have been the sticking point in the election of a plebeian as curio maximus; see Vishnia, p. 105.
- Livy 3.7.6–7; S. P. Oakley, A Commentary on Livy Books VI-X (Oxford University Press, 2005), p. 487; T. R. S. Broughton, The Magistrates of the Roman Republic (American Philological Association, 1951, 1986), vol. 1, p. 35. Broughton lists no earlier holders of the office. Aulus Sempronius Atratinus, the consul of 497 and 491 BC, was first interrex in 482 and thus presumably curio maximus, but is not identified as such.
- Tim Cornell, The Beginnings of Rome: Italy and Rome from the Bronze Age to the Punic Wars (Routledge, 1995), p. 116 online.
- Vishnia, State, Society, and Popular Leaders, p. 105.
- Cicero asserts that no plebeian had ever been rex sacrorum, but a Marcius had held the office, and no patrician Marcii are known; S. P. Oakley, A Commentary on Livy Books VI-X (Oxford University Press, 2005), p. 81.
- Livy 27.8 and 41.21; Vishnia, State, Society, and Popular Leaders in Mid-Republican Rome, pp. 105–107; Christopher John Smith, The Roman Clan: The gens from Ancient Ideology to Modern Anthropology (Cambridge University Press, 2006), p. 216 online.
- Oakley, A Commentary on Livy, p. 118, note 1 online.
- Andrew Lintott, The Constitution of the Roman Republic (Oxford University Press, 1999), p. 184.
- T. P. Wiseman, Remembering the Roman People (Oxford University Press, 2009), p. 43, note 55 online.
- Ovid, Fasti 2.527–32; H. H. Scullard, History of the Roman World 753 to 146 BC (Routledge, 1980), p. 68 online; Kurt A. Raaflaub, Social Struggles in Archaic Rome: New Perspectives on the Conflict of the Orders (Blackwell, 1986, 2005), p. 109.
- Georges Dumézil, "Interpretation: The Three Functions," in Structuralism in Myth (Taylor & Frances, 1996), p. 71 online.
- George Mousourakis, The Historical and Institutional Context of Roman Law (Ashgate, 2003), p. 52 online.
- Lintott, The Constitution of the Roman Republic, p. 184 online.