The following survey comprises all instances of Consuls or Consular Tribunes abdicating before the end of their term that are attested (number and date shown in bold type) or can plausibly be inferred (number and date in bold italics), along with uncertain or improbable cases (number and date in regular type). In most though not all occurrences, the ensuing interregnum is likewise on record.1
(1) 480 V. One Consul having been killed in action, his colleague declined a triumph and abdicated two months before the regular end of his term; an interregnum followed.2
(2) 451 V. The sources cannot agree on whether the Consuls abdicated after taking office (Cic. Rep. 2.61 and the FC = InscrItal 13.1: 26–27), or desisted from taking office altogether (Dion. Hal. 10.54.3–56.2; Livy 3.33.4). If abdication was involved, an interregnum may have followed; but Dionysios seems to imply that the Decemvirs were elected under the outgoing Consuls of 452 V, and the “abdication” tradition may have envisaged their election by the Consuls of 451.
(3) 444 V. The Military Tribunes with Consular Power—the first holders of that puzzling office—abdicated after three months in accordance with an augural decree, having been found vitio creati; an interregnum followed.3
Unfortunately, the new Consuls elected during the interregnum are clearly marked as suffecti (Livy 4.7.11; cf. Dion. Hal. 11.62.3), merely filling the remainder of the year when in fact they should have held office for a full twelve-month term.4 Dionysios notes that most of his sources only know of either the Tribunes in that year or the alleged suffect Consuls, although a few have both (πλὴν οὐκ ἐν ἁπάσαις ταῖς Ῥωμαϊκαῖς χρονογραφίαις ἀμφότεραι φέρονται, ἀλλ’ ἐν αἷς μὲν οἱ χιλίαρχοι μόνον, ἐν αἷς δ’ οἱ ὕπατοι, ἐν οὐ πολλαῖς δ’ ἀμφότεροι). Livy states that the names of these suffects appear in neither the early annals nor the fasti (neque in annalibus priscis neque in libris magistratuum inveniuntur): it was Licinius Macer who unearthed them from both the libri lintei and the Roman treaty with Ardea concluded in that year (4.7.10–12; cf. 4.7.4–7). Since the Tribunes’ abdication, however, apparently did not cause a change in the consular year (which, on Mommsen’s reconstruction, began on December 13 continuously from 449 to 4025), it must be considered fictional as told.
The electoral vitium adduced may furnish a clue: quod C. Curiatius qui comitiis eorum praefuerat parum recte tabernaculum cepisset (Livy 4.7.3). This evidently falls in the same category of mistake as happened to that summus augur, Ti. Sempronius Gracchus, when holding the consular comitia in 163: qui … tabernaculum vitio cepisset.6 When the vitium was discovered several months into the next year, 162, the Consuls elected under it promptly abdicated; yet the subsequent interregnum did not lead to a change in the beginning of the official year: instead, it produced a pair of suffecti to complete the current term.7 Unless the story from 444 be true as told, the solution adopted in 162 is the first of its kind unambiguously attested, and may serve as a terminus post quem for the first occurrence of the Tribunes’ abdication in the record, or at any rate, of such a detailed reason for their abdication.
As Frier showed long ago, there are no grounds for doubting the basic authenticity of Macer’s information: the pair of Consuls (L. Papirius Mugillanus and L. Sempronius Atratinus) he found in the Linen Books constitute the actual successors of the Military Tribunes of 444—successors who, for reasons irrecoverable, had fallen out of the “established” fasti and were unknown to the earlier annalists. Macer understood that this pair of Consuls had to come between the Tribunes of 444 and the Consuls of 443, but did not realize (or did not want to propose such an invasive alteration to the “established” chronology) that, to correct the record, an entire year (which we may call “444-A”), with Papirius and Sempronius as its regular Consuls, would have to be inserted between 444 V and 443 V. Instead, he made the Tribunes abdicate, to be succeeded, after an interregnum, by Papirius and Sempronius as suffects for the remainder of the year 444. Dionysios and Livy both accepted Macer’s reconstruction.8
(4) 402 V. Political and military considerations led to a senatus consultum instructing the Military Tribunes to leave office two-and-a-half months early, allegedly after first securing the election of their successors and without recourse to an interregnum. In consequence, the new Tribunes entered office on October 1 instead of December 13. There are grounds, however, to postulate an interregnum, if the premature termination of office in this year reflects historical reality at all.9
(5) 399 V. Broughton assumed another early abdication of Military Tribunes, based on Plutarch (Cam. 2.9).10
As is clear from λαχὼν Φαλερίοις καὶ Καπηνάταις πολεμεῖν (Cam. 2.10), Plutarch here conflates Camillus’ campaigns against Falerii (in 401, Livy 5.12.5) and Capena (in 398, Livy 5.14.5–7), but the context of his narrative evidently follows Livy’s (or a common source’s) account of 402 and 401, not 399 and 398: συνεστάλησαν ἐς τὰ τείχη surely corresponds to a M. Furio in Faliscis et Cn. Cornelio in Capenate agro hostes nulli extra moenia inventi (Livy 5.12.5, in 401), and the reason given for the magistrates’ premature termination (τοὺς ἄρχοντας ἐν αἰτίᾳ γενέσθαι καὶ μαλακῶς πολιορκεῖν δοκοῦντας) is exactly the same as Livy’s in 402 (sive culpa sive infelicitate imperatorum tam ignominiosa clades accepta, 5.9.1). The mistaken numeration of Camillus’ military tribunate of 401 as his second (cf. MRR 1: 82 n. 1, 84 n. 1) is likewise common to both authors.11 Thus there remains no evidence for an early abdication in 399. (Dion. Hal. 12.10, adduced by Broughton under 398 V for additional support, says nothing about Tribunes entering or leaving office.)
(6) 397 V. The Military Tribunes were deemed vitio creati and ordered to abdicate; an interregnum followed (Livy 5.17.1–4).
(7) 393 V. Abdication followed by an interregnum has been suggested, since the Fasti list a pair of suffect Consuls along with those originally elected. Degrassi (InscrItal 13.1: 30–31) restored [vitio facti abdicaru]nt, but Mommsen’s [non inieru]nt (CIL 12.1: 19) is much preferable.
(8) 392 V. Pestilence struck the City, and the Senate instructed the Consuls to abdicate, so as to enable a renovation of the auspices through an interregnum (Livy 5.31.5–8).
(9) 341 V. With the (First) Samnite War under way and the Latin War threatening, the Consuls of that year were prompted to abdicate early, so as to enable their successors to devote a greater part of their term to the campaign; religious scruples, however, prevailed to the effect that Consuls whose imperium had been curtailed in such fashion ought not to hold elections, and an interregnum ensued.12
(10) 321 V. After the disaster at the Caudine Forks the Consuls refrained from all public activity, except to appoint a Dictator comitiorum causa, who soon abdicated, vitio creatus; another Dictator followed, but likewise failed to carry out elections, for reasons unknown. Eventually, an interregnum came to pass: perhaps at the normal end of the consular year, though Livy’s quia taedebat populum omnium magistratuum eius anni rather suggests that the Consuls left office early.13
(11) 223 bc. The Consuls were found vitio creati and compelled to abdicate immediately after their triumphs. An interregnum followed, and the start of the consular year shifted from (probably) May 1 to March 15.14
(12) 220 bc. The Chronographer of 354 has Levino et Scevola, meaning M. Valerius Laevinus and an unidentified Mucius Scaevola, perhaps Q. pr. 215. The other sources show C. Lutatius Catulus and L. Veturius Philo; both campaigned in Gaul (Zonar. 8.20). Since Valerius Laevinus is attested with a second consulate in 210 (FC = InscrItal 13.1: 46–47; Livy 29.11.3; 30.23.5), the Chronographer’s notice must be correct, and both Consuls must have been vitio facti. But it remains unknown whether they abdicated early into their term, or never entered office.15 If the former, an interregnum must have followed; if their successors took office on or after April 1, they were the first suffecti proper, completing the original Consuls’ term without a change in the beginning of the consular year.
(13) 162 bc. The Consuls abdicated, having been deemed vitio creati; in a major departure (unless this happened already in 220) from previous practice, however, the ensuing interregnum apparently produced two suffects to complete the term, rather than regular Consuls starting a new official year.16
(14) 154 bc. The Consuls left office two-and-a-half months early so as to enable their successors to take command in Spain sooner; in consequence, the beginning of the official year shifted from March 15 to January 1.17
An interregnum is not attested but probable enough: if the precedent of the year 341 (see #9 above) was already known, it could hardly be ignored in 154; if not, it is difficult to see why it should have been invented without an actual case to serve as a model (and, presumably, in need of a justifying precedent). Unless, of course, the Consuls of 153 had already been elected when the decision was made to accelerate their entrance into office; but elections completed some three months before year’s end, though possible, command scant likelihood in the second century.
(15) 152 bc. A prodigium is said to have prompted the abdication of all magistrates; an interregnum must have followed, but it yielded no suffects to complete the term, nor another shift in the start of the consular year.
The notice has not always attracted credence: Broughton ignored it. However, Jahn’s explanation may well point in the right direction: although all the magistrates in Rome resigned, a delay in communication with the Consul M. Claudius Marcellus, on campaign in Spain, was inevitable; and notice of his abdication (assuming he learned of the necessity before it became moot, that is, still in 152) did not reach Rome until close to the end of the year—too close to make electing suffects worth the while, or move up the start of the next official year.18