1 An Urgent Summons and a Terrible Charge

Evidence of what happened to M. Scribonius Drusus Libo is frustratingly superficial. Only summaries and passing references survive. Tacitus provides the longest account, but the contemporary Velleius, the younger Seneca, Suetonius, and Dio also supply information.¹ An official record of Drusus Libo’s posthumous conviction survives in the Fasti Amiternini:

Fer. ex s.c.q.e.d. nefaria consilia quae de salute Ti. Caes. liberorumque eius et aliorum principum civitatis deq(ue) r.p. inita ab M. Libone erant in senatu convicta sunt.

A holiday on account of the decree which (was passed) because the wicked plans commenced by M. Libo concerning the safety of Tiberius Caesar and his children and other men of consular rank and also concerning the State were defeated in the senate.²

The senate convened to investigate the allegations from 11 to 13 September ad 16, a period usually spent enjoying the Roman games (Ludi Romani).³ The scenario was therefore unusual and foreboding. But suspicion of Drusus Libo had been developing for some time:

 Firmius Catus senator, ex intima Libonis amicitia, iuvenem inprovidum et facilem inanibus ad Chaldaeorum promissa, magorum sacra, somniorum etiam interpretes impulit, dum proavum Pompeium, amitam Scriboniam quae quondam Augusti coniunx fuerat, consobrinos Caesares, plenam imaginibus domum ostentat, hortaturque ad luxum et aes alienum, socius libidinum et necessitatum, quo pluribus indiciis inligaret.

Firmius Catus, a senator and close friend of Libo, urged the short-sighted young man, given to empty things, to resort to the promises of astrologers, the rites of magicians, and also dream interpreters, reminding him of his great-grandfather Pompeius, his paternal aunt Scribonia, former wife of Augustus, his imperial cousins, his house crowded with ancestral images, and urging him to extravagance and debt: Firmius associated himself in these debaucheries and embarrassments in order to entangle Libo in more evidence.⁴

Catus, having collected witnesses, took his evidence to a certain Vescularius Flaccus, a friend of Tiberius’. Catus sought an audience with the princeps, but, having considered the evidence passed on by Flaccus, Tiberius declined. We are told that Tiberius then distinguished Drusus Libo with a praetorship and invited him to dinners.⁵ Sometime later (Suetonius has two years) fresh and damning evidence emerged.⁶ A necromancer named Junius had informed a prosecutor (delator), C. Fulcinius Trio, that Drusus Libo had paid him to invoke dead spirits. Suddenly chaos:

statim corripit reum, adit consules, cognitionem senatus poscit. Et vocantur patres, addito consultandum super re magna et atroci.

Immediately he [Trio] seized the accused, approached the consuls, and called for an investigation in the senate. And so the fathers were called, it being added that they were to deliberate upon a great and terrible matter.⁷

Drusus Libo, informed of the charge, sought out an advocate but, despite the support of noble women (primores feminae), was unsuccessful. The investigation began the next day, with the defendant carried to the doors of the senate in a litter accompanied by his brother, who was consul ordinarius for that year. Tiberius read out both the charge and the names of the delatores: Fulcinius Trio, Firmius Catus, Fonteius Agrippa, and C. Vibius Serenus. Drusus Libo defended himself.⁸

The charges were designed to erode the defendant’s credibility: Drusus Libo had allegedly consulted someone as to whether he would have enough money to cover the Appian road to Brundisium, followed by similar accusations. Then the bombshell:

Uni tamen libello manu Libonis nominibus Caesarum aut senatorum additas atrocis vel occultas notas accusator arguebat.

On one paper sinister or cryptic marks had been added to the names of Caesars or senators in Libo’s hand, the accuser alleged.⁹

The evidence had an immediate effect. Drusus Libo denied the allegation, the prosecutor pressed, and so the defendant’s slaves were sold to the State for interrogation. Thus the first day concluded. Before going home, Drusus Libo asked his relative P. Quirinius to deliver final pleas to Tiberius, but the desperate tactic was obstructed by the constitutional diligence of the princeps, who responded ‘that he should ask the senate’: responsum est ut senatum rogaret. Arriving home, Drusus Libo was confronted by troops in and around his house. Disturbed by the soldiers he relinquished hope and committed suicide. Seneca places Scribonia at the scene. It may be a literary convention, but Scribonia’s presence does make sense. She certainly ranked among the primores feminae and, moreover, had supported other relatives in their moments of disgrace. Scribonia apparently encouraged her great nephew not to anticipate the executioner. The advice was ignored.

Death did not bring the investigation to a close. At some stage, probably when the verdict was read out, Tiberius swore an oath that he would not have supported death: iuravitque Tiberius petiturum se vitam quamvis nocenti, nisi voluntariam mortem properavisset. Many obviously considered death to be the appropriate punishment. Motions to remove Drusus Libo from public memory (damnatio memoriae) were then proposed. M. Aurelius Cotta Maximus Messalinus¹⁰ proposed that Drusus Libo’s image should not be carried in the funeral procession of any of his descendants, and Cn. Lentulus proposed that no Scribonius should bear the cognomen Drusus.¹¹Public acts of thanks were then performed. Offerings were made to Jupiter, Mars, and Concord, and 13 September was to be observed as a festival thereafter.¹² These last decrees were suggested by L. Pomponius Flaccus,¹³ Asinius Gallus, M. Papius Mutilus,¹⁴ and L. Apronius. Tacitus mentions another, but only L. P…remains. The initials could refer to at least four known senators during the period.¹⁵ Drusus Libo’s property was then divided among the delatores, and those delatores who were senators were awarded/received a praetorship, which probably means that Tiberius personally sponsored their candidacy.¹⁶ Finally, a decree was passed expelling occult practitioners from Italy, two of whom, L. Pituanius and P. Marcius, were put to death.¹⁷

Most recent scholars, following Tacitus, dismiss Drusus Libo as relatively harmless: a stupid young man pursued by covetous prosecutors and left for dead by a hypocritical regime.¹⁸ But certain items become incredible if the entire episode was orchestrated for the benefit of ravenous delatores: the fact of an emergency meeting of the senate (and during the Ludi Romani); the nature of the charge; Drusus Libo’s inability to find an advocate; the continuation of the investigation after death; placing Drusus Libo into custody, rather than encouraging voluntary exile; the implementation of damnatio memoriae; marking 13 September a holiday, and the invocation of Concord. Concord is particularly suggestive. Her presence implies that Drusus Libo’s disgrace accompanied a profound rupture in Rome’s socio-political fabric. There is, therefore, a major discrepancy between the facts of the case as they have come down to us, and the explanation provided by Tacitus. As Rogers and Levick supposed, and I shall argue, the conspiracy of the psuedo Agrippa Postumus (i.e. the slave Clemens) in ad 16 best explains the contradiction: Drusus Libo was supporting a plan to bring down the government.¹⁹ The structure of the argument will fall roughly into two parts. First I shall argue that Tiberius and his government treated Drusus Libo seriously rather than as a harmless fool. I shall then propose a new historical interpretation for the years 6 bc–ad 16 to demonstrate that Tiberius’ right was seriously contested, and that his opponents had been supporters of Augustus’ grandsons. We shall start by considering the fact that Drusus Libo was forced to endure a senatorial investigation.

Only suspicion dogged Drusus Libo before the senate meeting, but real trouble emerged when the necromancer he consulted, a certain Junius, proved more ambitious than himself. Impressed by the situation, Junius sought out the most celebrated prosecutor of the day (celebre ingenium). L. Fulcinius Trio was decisive:

statim corripit reum, adit consules, cognitionem senatus poscit. Et vocantur patres, addito consultandum super re magna et atroci.

Immediately he [Trio] seized the accused, approached the consuls, and called for an investigation in the senate. And so the fathers were called, it being added that they were to deliberate upon a great and terrible matter.²⁰

An extraordinary meeting of the senate (senatus indictus) to determine Drusus Libo’s intention signals an emergency. During the late Republic the senate might respond to the possibility of revolution by asking the consul to ‘see to it that the State should suffer no harm’, the so-called senatus consultum ultimum (SCU).²¹ But this was conceptually impossible in the early Principate, when the safety of the res publica was supposed to depend on a princeps.²² Tiberius apparently uttered the formula once, when, in ad 24, the consul L. Visellius Varro prosecuted C. Silius Caecina Largus, but Tiberius’ intention is suspect:

Precante reo brevem moram, dum accusator consulatu abiret, adversatus est Caesar: solitum quippe magistratibus diem privatis dicere: nec infringendum consulis ius, cuius vigiliis niteretur ne quod res publica detrimentum caperet. Proprium id Tiberio fuit scelera nuper reperta priscis verbis obtegere.

The defendant requested a brief delay so that the accuser could retire from the consulate, but Caesar opposed: ‘It was by all means usual for magistrates to name a day for the trial of private citizens: nor should the right of the consul be infringed, by whose vigilance it depends that the State should suffer no harm.’ It was characteristic for Tiberius to conceal his latest evil inventions with ancient words.²³

Tiberius’ opinion, irrefutable and cynical, had the effect of presenting Silius as a danger to the State.²⁴ To justify the consul’s participation (who may have been driven by personal enmity), Tiberius evoked through the language of the SCU an atmosphere of emergency. The device was, moreover, used to convey another message. Velleius praised Tiberius for, among other things, restoring the senate’s maiestas.²⁵ With less enthusiasm, Tacitus, Suetonius, and Dio have the senate playing a larger role under Tiberius than Augustus.²⁶ Their works contain, in fragmentary form, Tiberius’ most important message to posterity, something like: ‘I simply facilitate imperial administration, while the consuls with the senate run the show.’ By invoking the SCU, Tiberius implied that his supreme position in no way affected the traditional potestas and auctoritas of the consuls: Tiberius’ Principate was in practice a restored Republic! This improvised application of rhetorical colour does not explain why Drusus Libo was scrutinized in the senate rather than a court. The explanation lies instead with the senate’s established right to hear evidence of conspiracy when due process was impracticable.

L. Fulcinius Trio did not waste time by seeking out the praetor presiding over the quaestio maiestatis, instead, as with all national emergencies, he went straight to the consuls. Ordinarily, Trio would have sought out the appropriate praetor and applied to prosecute Drusus Libo. The praetor would then have summoned Drusus Libo to appear before him to discuss the charge (nominis delatio). Satisfied that the evidence deserved trial, the praetor would then publish the charge and name Drusus Libo defendant (reus) before fixing a day for the trial to begin. In cases of maiestas the reus was given ten days in which to organize a defence or else enter into exile.²⁷ Trio hurried to the consuls because the evidence demanded their knowing and the senate’s immediate response: the idea of seeking out the appropriate praetor, and thus giving Drusus Libo time to expedite his plans, would not have suggested itself. The praetor would instead be asked to consider the matter only once the senate had published its opinion (praeiudicium), at which point, had Drusus Libo not taken his own life, the iudices would have been hard pressed to produce anything but a verdict of guilty. In seeking out the consuls, Trio knew well that precedent justified his decision.

On 18 October 63 bc M. Licinius Crassus, M. Marcellus, and Q. Caecilius Metellus provided to the consul, M. Tullius Cicero, evidence that suggested an impending insurrection by L. Sergius Catilina. Cicero summoned the senate the next day. Nothing came of this meeting but further suspicion that Catiline was up to no good, but when more damning evidence emerged two days later senators were again summoned, and this time the SCU was passed. For five weeks Cicero sought proof that a massacre was imminent, until finally a group was caught in the early hours of 3December leaving Rome with sealed letters for Catiline. Cicero led those captured to the temple of Concord where senators were assembled. Having been examined by the senate, Catiline’s associates were put under arrest and for two days their fate was uncertain while senators considered the options. On 5 December they were put to death. Whilst the decision to execute the prisoners was controversial, the senate’s right to investigate the matter was not. This right was acknowledged even, or perhaps especially, during the early Principate.

In 26 bc, C. Cornelius Gallus, prefect of Egypt, was alleged to have extorted from provincials, put up images of himself in Egypt, inscribed a list of his achievements on the pyramids, and slandered Augustus in private.²⁸ Augustus reacted to the allegations by publicly withdrawing friendship (renuntiatio amicitiae) and inviting the senate to investigate the matter:

metu nobilitatis acriter indignatae, cui negotium spectandum dederat imperator…

in fear of the keenly disgusted nobility, to whom the emperor had given the affair to be looked into…²⁹

The plundering of Egypt and thus the tempting of local inhabitants to revolt—which was not unheard of, especially for the Alexandrians—was for Augustus a matter worthy of senatorial scrutiny.³⁰ The productive capacity of Egypt was vital to the overall health of the economy, and hence the empire. Senators, on finding sufficient proof that Gallus was guilty, agreed that his actions were of national significance:

καὶ ἡ γερουσία ἅπασα ἁλω̑ναί τε αὐτὸν ἐν τοι̑ς δικαστηρίοις καὶ ϕυγει̑ν τη̑ς οὐσίας στερηθέντα, καὶ ταύτην τε τῳ̑ Aὐγούστῳ δοθη̑ναι καὶ ἑαυτοὺς βουθυτη̑σαι ἐψηϕίσατο.

The whole senate voted that he should be convicted in the courts and, having been deprived of his estate, exiled, and that his estate should be given to Augustus, and that they themeselves should offer sacrifices.³¹

Gallus committed suicide before the decree took effect. The pressure on the quaestio to rubber-stamp the senate’s praeiudicium was enormous: a verdict of not guilty was improbable and Gallus knew it. Four years later, in 22 bc, the res publica supposedly faced a more serious threat when the noble L. Terentius Varro Murena and a certain Fannius Caepio were put to death for planning revolution.³² Though the sources do not explicitly give the senate a role before the trial took place, inference and logic would suggest that it had one.

No detailed account survives of the episode, but enough remains to construct a basic narrative: a plot was formed to bring down Augustus’ government;³³ a certain Castricius gained knowledge of the conspiracy and informed Augustus.³⁴ Augustus called for his most trusted advisers, one of whom was Maecenas. Maecenas related the information to his wife, Terentia, who in turn told her brother L. Terentius Varro Murena.³⁵ The conspirators—aware that the game was up—fled Rome. At some point, probably early the next day, a decision was made to send troops after the pair.³⁶ Tiberius then took the matter to the praetor presiding over the quaestio maiestatis and named Caepio as defendant.³⁷ Caepio was condemned in absentia; Murena was then subjected to the same process. Caepio was finally caught in Naples.³⁸ Murena was caught with a peripatetic philosopher from Seleuceia named Athenaeus, who, we are told, supported popular politics.³⁹ Those caught were taken to Rome and put to death, except Athenaeus, who was found not guilty and released. Finally, thanks were voted as if it were a victory.⁴⁰

The decision to send troops after the conspirators, accompanied no doubt by a public declaration that the pair were wanted for questioning and ought to be considered fugitives, would have come from the senate. Senators may even have suggested that the pair ought to be tried for maiestas. It would certainly explain the voting of supplicationes after the trial. It is inconceivable that Augustus was so clumsy as to take a matter of national importance straight to the praetor, when he had spent so much energy convincing the public, and especially senators, that his new res publica was built upon senatorial auctoritas, and especially impolitic to exclude the senate from something which belonged to it.⁴¹ I believe that on hearing news that Caepio and Murena had fled Rome, Augustus immediately summoned senators for the purpose of producing a united response. Tiberius then approached the praetor to prosecute both men in absentia, arguing in court that their fleeing was in fact an attempt to enter into exile and should therefore be treated as confession.⁴² Most in the jury agreed. The men were brought back to Rome for execution because they were not trusted in exile. The role of the senate was vital here, as it must also have been for the investigations into the acts of the elder Julia, Titus Labienus, anti-government pamphlets in ad 6, Agrippa Postumus in ad 7, and Falanius and Rubrius in ad 15.⁴³ The idea that the senate was the appropriate space for the discussion of matters supposedly concerning the safety and health of the res publica compelled Tiberius to claim in ad 20 that:

Id solum Germanico super leges praestiterimus, quod in curia potius quam in foro, apud senatum quam apud iudices de morte eius anquiritur.

In this way only we will have placed Germanicus above the laws (super leges), that his death will be investigated in the curia rather than in the forum, before the senate rather than before the judges.⁴⁴

The Senatus Consultum de Pisone Patre reveals that senators were not limited to discussing the circumstances of Germanicus’ death:

Ti(berius) Caesar divi Aug(usti) f(ilius) Aug(ustus) pontifex maxumus, tribunicia potestate XXII, co(n)s(ul) III, designatus IIII ad senatum rettulit qualis causa Cn. Pisonis patris visa esset et an merito sibi mortem conscisse videretur…et quid de Visellio Karo et de Sempronio Basso, comitibus Cn. Pisonis patris, iudicaret senatus…

Tiberius Caesar Augustus, son of the divine Augustus, pontifex maxumus, in the twenty-second year of his tribunician power, having been consul three times, consul designate for the fourth time, referred (the following) to the senate: how the case of Cn. Piso the father had seemed, and whether his suicide seemed justified…and what the senate judged concerning Visellius Karus and Sempronius Bassus, members of Cn. Piso the father’s retinue…⁴⁵

Before Piso had even reached Rome, where accusations of murder awaited, the younger Drusus had been forced to remind a growing mob that men were innocent till proved guilty.⁴⁶ The plea to justice had little effect. While senators were in session a large group allegedly assailed the doors of the senate house:

Simul populi ante curiam voces audiebantur: non temperaturos manibus si patrum sententias evasisset. Effigiesque Pisonis traxerant in Gemonias ac divellebant, ni iussu principis protectae repositaeque forent.

At this same time voices of the people were heard in front of the Curia: they promised violence if he should evade the opinions of senators. They dragged statues of Piso to the Gemonian stairs and were breaking them up when, by order of the princeps, they were rescued and replaced.⁴⁷

Popular unrest made operation of the regular court impossible. The auctoritas of the senate was needed to settle excited citizens and arrest the possibility of further violence. As with Augustus’ decision regarding allegations against Gallus, Tiberius decided that politics demanded the senate’s participation.⁴⁸

Piso subsequently suffered damnatio memoriae because his suicide was found deficient in merit.⁴⁹ Judging the indictments against the comites, the senate decreed:

Visellio Karo et Sempronio Basso comitibus Cn. Pisonis patris et omnium malificiorum socis ac ministris, aqua et igne interdici oportere ab eo pr(aetore), qui lege{m} maiestatis quaereret, bonaq(ue) eorum ab pr(aetoribus), qui aerario praeesse〈n〉t, venire et in aerarium redigi placere.

That Visellius Karus and Sempronius Bassus, members of Cn. Piso the father’s retinue, allies and assistants in all of his wicked crimes, ought to be interdicted from fire and water by the praetor who investigates (crimes) under the lex maiestatis, and that their property be sold by the praetors responsible for the aerarium, and that the collected proceeds be placed in the aerarium.⁵⁰

The senate passed its judgment on the guilt of the accused and prescribed the appropriate punishment, but the legal implementation of these decisions required the quaestio: as with its investigation into Gallus forty-five years earlier, the senate’s judgment was preliminary not de iure.⁵¹ As the above cases make clear, the senate had an important role within the Roman constitution that survived the transition from the late Republic to the governments of Augustus and Tiberius. It remained the space in which matters perceived to be national emergencies were discussed. Some cases, such as those of Falanius and Rubrius, were put to senators because the decision could have far-reaching legal effects, while others, such as allegations against Catiline’s associates, and Caepio and Murena, required an immediate response to a perceived threat. The fact that Trio hurried to the consuls, who in turn summoned an emergency meeting of the senate, is therefore our first piece of evidence that Drusus Libo was thought to have posed a serious and immediate threat. It is now time to consider the charge.

Et vocantur patres, addito consultandum super re magna et atroci.

And so the fathers were called, it being added that they were to deliberate upon a great and terrible matter.⁵²

The spectacle of senators hastily summoned ‘to deliberate upon a great and terrible matter’ led to a generally held impression that Drusus Libo was finished before even the submission of evidence. Friends and family displayed their pessimism by refusing appeals to both amicitia and pietas. In Tacitus’ narrative, the consuls’ decision to summon senators was in response to evidence that Drusus Libo had employed a necromancer to raise dead spirits. This was not a crime. The crime lay in the nature of his conversation with the necromancer.

Though details of the indictment are not extant, most scholars assume that maiestas was at least one of the charges. But while some hold that his occult interests were the basis of the maiestas charge, others believe that they were merely incidental, and that occult practices did not then constitute prima facie maiestas, even when the princeps was affected.⁵³ Rutledge, whose notable contribution is the latest, has put forward a third possibility: Drusus Libo was never indicted for maiestas, only occult practices in so far as they contravened the lex Cornelia de sicariis et veneficis.⁵⁴ A reconsideration of the relationship between Drusus Libo’s alleged activity and Roman criminal law is therefore warranted.

In ad 11 Augustus responded to interest in his failing health by publishing his horoscope and forbidding the practice thereafter. No Roman was to employ a seer to discover one’s own, or another’s, time of death:

καὶ τοι̑ς μάντεσιν ἀπηγορεύθη μήτε κατὰ μόνας τινὶ μήτε περὶ θανάτου, μηδ’ ἂν ἄλλοι συμπαρω̑σίν οἱ, χρα̑ν· καίτοι οὕτως οὐδὲν τῳ̑ Αὐγούστῳ τω̑ν καθ’ ἑαυτὸν ἔμελεν ὥστε ἐκ προγραϕη̑ς πα̑σι τὴν τω̑ν ἀστέρων διάταξιν, ὑϕ’ ὡ̑ν ἐγεγέννητο, ϕανερω̑σαι. οὐ μὴν ἀλλ’ ἐκει̑νό τε ἀπει̑πε…

It was forbidden for seers to prophesy to anyone alone or on the topic of death, even if others were present. Even so, Augustus was so far from caring about such matters when he himself was concerned that he published by edict for all to know the arrangement of the stars under which he had been born. Nevertheless he forbade this practice.⁵⁵

Augustus’ response was limited. Astrology was not criminalized, only consultations between one person and a seer and questions about death, which must mean questions about both death (mors) and health (salus). Augustus’ official horoscope (lacking a time of death)⁵⁶ was certainly published to overwhelm the widespread interest in his health, though a question de salute principis was not specifically made a crime. Augustus’ personality was sufficiently protected by the general ban on questions de salute alicuius - a further prohibition would have been redundant. But did Augustus intend a breach of the ban to constitute a breach of the lex maiestatis?

Shortly after the investigation into Drusus Libo a senatus consultum outlawed all practice of astrology and magic in Rome.⁵⁷ Another—passed sometime later—determined that all Roman mathematici, chaldaei, and harioli should be interdicted from fire and water and have their property confiscated, whilst their foreign counterparts should be put to death.⁵⁸ We cannot be sure to what extent the decrees differed in penalty, since they seem to have been telescoped over time, but obviously the first was not considered sufficient. A description of the second survives in Ulpian:

Denique extat senatus consultum Pomponio et Rufo cons., factum, quo cavetur, ut mathematicis Chaldaeis ariolis et ceteris, qui simile inceptum fecerunt, aqua et igni interdicatur omniaque bona eorum publicentur, et si externarum gentium quis id fecerit, ut in eum animadvertatur…Saepissime denique interdictum est fere ab omnibus principibus ne quis omnino huiusmodi ineptiis se inmisceret, et varie puniti sunt ii qui id exercuerint, pro mensura scilicet consultationis. Nam qui de principis salute, capite puniti sunt vel qua alia poena graviore adfecti…

In short, a senatus consultum from the consulship of Pomponius and Rufus is extant in which it is laid down that astrologers, Chaldaei, seers and others who engage in similar practices are to be interdicted from fire and water and all of their property shall be confiscated, and if a foreigner has done this he should be punished with death…A prohibition has often been imposed by almost every emperor on those who meddle at all in such follies, and those who practice it have been variously punished, obviously according to the seriousness of the consultation. Those who have inquired into the safety of the princeps have been put to death or have had some rather serious punishment inflicted on them…”⁵⁹

Tacitus, Suetonius, and Dio also give versions of the decree/s:

Facta et de mathematicis magisque Italia pellendis senatus consulta.

Decrees of the senate were also passed expelling mathematici and magi from Italy.⁶⁰

Expulit et mathematicos sed deprecantibus ac se artem desituros promittentibus veniam dedit.

He also expelled the mathematici but pardoned those who came to him promising to give up their art.⁶¹

…τούς τε ἀστρολόγους καὶ τοὺς γόντας, εἴ τέ τινα ἖τερον καὶ ὁποιονου̑ν τρόπον ἐμαντεύετό τις, τοὺς μὲν ξένους ἐθανάτωσε, τοὺς δὲ πολίτας, ὅσοι καὶ τότε ἕτι, μετὰ τὸ πρότερον δόγμα δι᾽ οὑ̑ ἀπηγόρευτο μηδὲν τοιου̑τον ἐν τῃ̑ πόλει μεταχειρίζεσθαι, ἐσηγγέλθησαν τῃ̑ τέχνῃ χρώμενοι, ὑπερώρισε· τοι̑ς γὰρ πειθαρχήσασιν αὐτω̑ν ἄδεια ἐδόθη.

As for the astrologers, magicians and anyone who practiced divination in any other way whatsoever, he put the foreigners to death and banished all the citizens who, even then, were accused of still practicing the art after the former decree by which it was forbidden to be involved in any such activity in the city; for to those amongst them who obeyed immunity was given.⁶²

As a general description we can add a statement by the jurist Paulus:

qui de salute principis vel summa rei publicae mathematicos hariolos haruspices vaticinatores consulit, cum eo qui responderit capite punitur.

One who consults mathematici, harioli, haruspices or soothsayers concerning the safety of the princeps or the wellbeing of the State, along with one who responds (i.e. the practitioner), is capitally punished.⁶³

Expulsion of all citizen ‘astrologers, chaldeans, seers and others who engage in similar practices’ is a purge: Tiberius had criminalized the lot.⁶⁴ The ban was soon ignored, since astrologers can be found working in Rome four years later, but as a legal measure it marks a radical departure from Augustus’ approach. Both Ulpian and Paulus make reference to salus principis but the words fere omnes principes in Ulpian need not encompass Augustus, and it is clear from Paulus’ reference to caput that he is citing a much later interpretation, when interdiction had ceased to be the penalty for that crime.⁶⁵ Ulpian thus began his discussion with the decree of ad 17 because it was antecedent to consultations de salute principis being interpreted under the heading maiestas. Allegations against Aemilia Lepida four years later demonstrate the development.⁶⁶ Charges of adultery (adulteria), poisoning (venena), and asking seers about the house of Caesar (quaesitum Chaldaeos in domum Caesaris) were added to an indictment for false testimony (falsum). Quaesitum Chaldaeos in domum Caesaris was argued to have constituted maiestas.⁶⁷ Tiberius asked the senate not to consider the charge of maiestas, and later when the defendant’s slaves were handed over to the consuls he asked that the interrogation not include the issue concerning his family.⁶⁸ The incarceration and interrogation of slaves was administered according to the lex Iulia de adulteriis, which was not a capital offence.⁶⁹ When a capital offence was discovered, it came under the lex Cornelia de sicariis et veneficis: an intention to poison her ex-husband.⁷⁰ Since Aemilia did not plan to harm Tiberius or his family, the allegation of astrology was allowed to slide. At the very worst she had too liberally indulged in silly games fashionable with aristocrats.⁷¹ The prosecutors saw things differently.⁷² They understood that the senatus consulta of ad 16 and 17 had more significant legal effect than mere outlawry; any enquiry into any aspect of the imperial family was prima facie maiestas. The only known bridge between the senatus consultum of ad 11, the senatus consulta of ad 16 and 17, and the investigation of Aemilia Lepida is the case of Drusus Libo.⁷³

Since C. Vibius Serenus was chosen to represent the prosecution in the peroration, he must at some stage have dealt with Fulcinius Trio’s evidence.⁷⁴ Vibius began with a rhetorical device for character assassination: Drusus Libo’s addiction to occult practices evidenced an ambitious spirit.⁷⁵ Other tales were told and when the defendant had been sufficiently humiliated, Vibius submitted evidence that shocked Drusus Libo into denial and forced the sale of his slaves to the actor publicus. According to Tacitus:

Uni tamen libello manu Libonis nominibus Caesarum aut senatorum additas atrocis vel occultas notas accusator arguebat. Negante reo adgnoscentis servos per tormenta interrogari placuit…Ob quae posterum diem reus petivit domumque digressus extremas preces P. Quirinio propinquo suo ad principem mandavit.

On one paper sinister or cryptic marks had been added to the names of Caesars or senators in Libo’s hand, the accuser alleged. When the defendant denied this it was resolved to interrogate under torture the slaves who recognized the handwriting…On account of this the defendant asked to adjourn till the next day, and having departed for home entrusted his final prayers to the emperor to his relative P. Quirinius.⁷⁶

Drusus Libo did not kill himself until after Tiberius refused his plea, but the driving force was the senate’s explosive reaction to this single libellus. He realized, on witnessing senators’ expressions, that the situation was hopeless. A list of imperial and senatorial names is in itself suggestive, but it became impressive when the accompanying marks were described as atrocis vel occultas.⁷⁷ It is clear from the official commemoration of the trial that a majority in the senate agreed with the prosecutor’s description:

 Fer. ex.s.c.q.e.d. nefaria consilia quae de salute Ti. Caes. liberorumque eius et aliorum principum civitatis deq(ue) r.p. inita ab M. Libone erant in senatu convicta sunt.

A holiday on account of the decree which (was passed) because the wicked plans commenced by M. Libo concerning the safety of Tiberius Caesar and his children and other men of consular rank and also concerning the State were defeated in the senate.⁷⁸

The words de salute Ti. Caes. Liberorumque eius et aliorum principum civitatis so parallel the description of the libellus—nominibus Caesarum aut senatorum—that the decree clearly inspired Tacitus’ report, though the poetical atrox is probably Tacitus’ own touch. The libellus was also the clearest evidence of the res magna et atrox which had prompted the emergency investigation in the senate - it was supplied by the necromancer Junius. It is not hard to imagine how Junius came to possess the document: Drusus Libo wrote the list at home before taking it to Junius for consultation; Junius explained that he needed to hold on to it: ‘the incantations will take a few days’; Drusus Libo left the document with Junius, who, as soon as the situation allowed, took it to one of the best prosecutors in Rome, L. Fulcinius Trio.

The senatus consulta that followed the investigation and the execution of the two mathematici, L. Pituanius and P. Marcius, reinforce the link between Junius’ libellus and the res magna et atrox. Pituanius was flung from the Rock, whilst the consuls decapitated Marcius outside the Esquiline Gate at sound of trumpet.⁷⁹ Though they were probably tried first, the decision to execute was discretionary, much like the executions of Caepio and Murena.⁸⁰ Pituanius and Marcius were evidently guilty of acts more serious than a mere breach of the Augustan edict of ad 11, which was not a capital offence. More probably they were judged to have participated in Drusus Libo’s conspiracy by way of their talents.

The role of the occult in this episode weighed on the mind of Tiberius, and in doing so forged a bridge between the decree of ad 11 and those of ad 16 and 17. Debate in the senate during the drafting of the latter, however, shows that a total ban was not universally favoured:

καὶ σύμπαντες δ’ ἂν οἱ πολι̑ται καὶ παρὰ γνώμην αὐτου̑ ἀϕείθησαν, εἰ μὴ δήμαρχός τις ἐκώλυσεν. ἔνθα δὴ καὶ μάλιστα ἄν τις τὸ τη̑ς δημοκρατίας σχη̑μα κατενόησεν, ὅτι ἡ βουλὴ του̑ τε Δρούσου καὶ του̑ Τιβερίου, συνέπαινος Γναίῳ Καλπουρνίῳ Πίσωνι γενομένη, κατεκράτησε, καὶ αὐτὴ ὑπὸ του̑ δημάρχου ἡττήθη.

And all the citizens would have been acquitted contrary to his [Tiberius’] opinion, if a certain tribune had not obstructed. And here indeed one would particularly observe the form of democratic government, in so far as the senate, being in agreement with Cn. Calpurnius Piso, overruled Drusus and Tiberius, and was itself defeated by the tribune.⁸¹

Senators believed that a purge of occult practitioners (citizens) was unjustified, and were willing to oppose Tiberius publicly. Senators who had recently passed posthumous penalties upon the memory of Drusus Libo and, perhaps, ordered the execution of his accomplices were now agreed that Drusus and Tiberius were overstepping the mark. Interest in the occult affected every level of society. High levels of participation made Tiberius’ policy unenforceable, and senators knew it. Opposition was perhaps also encouraged by a belief that the occult played only a subsidiary role in the Drusus Libo affair, as can be seen in the description of his intention in the sources.

Tacitus describes Drusus Libo’s intentions with moliri res novas; Suetonius has res novas clam moliebatur; Dio has δόξαντά τι νεωτερίζειν; Velleius has nova molientem and scelerata consilia; Seneca has maiora sperantis quam illo saeculo quisquam sperare poterat aut ipse ullo; while the government itself used nefaria consilia…de r.p.⁸² An intention to cause revolution will have always resulted in maiestas, but a diminution of maiestas will not always have been caused by an intention to cause revolution; the sources unequivocally agree that senators believed Drusus Libo was aiming at revolution. The link to divination rested on the allegation, accepted as fact, that the defendant had given the list of names to a necromancer. It is here pertinent to refute the theory of Ogden that the dead spirits raised by Junius were meant to kill the people listed on the parchment.⁸³ Lucan, Heliodorus, and Dio are our best sources for the Roman conception of necromancy, and they show that dead spirits were not roused to kill but to prophesy.⁸⁴ Ogden has nevertheless drawn our attention to an important problem: how do we combine the parchment with the nature of Junius’ expertise? The parchment on its own required a context. A context could only be supplied by a question. Vagueness would have been important, but it would need to be specific enough to gain an adequate answer. The question also had to be such that Tiberius could show indifference, whether real or feigned. Suspicion would not be aroused by something like ‘will a certain venture be profitable?’⁸⁵, but perhaps by ‘what does my future hold should anything unfortunate happen to the men on this list?’ If this question were put to Junius in combination with a written list comprising members of the imperial family and other important men of State, it would account for both Junius’ initial reaction and that of senators upon hearing the evidence.

Junius judged immediately that Drusus Libo was up to no good and wanted no part in it. Drusus Libo was deemed to have been plotting a coup in which the intended victims were represented on the list; the suspicion formed the basis of the indictment. The charge of having consulted magical practitioners, however, played only a subsidiary role. Its use as evidence was more important. Without obvious proof of Drusus Libo’s plot, senators could only infer intent from Junius’ evidence. The fact that he also breached the edict of ad 11 was probably an afterthought. As a result of this investigation the door was left open for such questions to be considered treasonable in the future, but that reaction (favoured by a minority) should not blind us to the true nature of the charge, which was intent to cause revolution as interpreted under the lex maiestatis. Still, clarification of the charge does not make Drusus Libo an actual revolutionary. He is considered a dupe by most scholars, foolish enough to fall prey to more ferocious members of society, delatores. Such a view is certainly supported by at least two ancient writers. Seneca writes: adulescentis tam stolidi quam nobilis, ‘a young man, more stupid than noble’, while Tacitus has: iuvenem inprovidum et facilem inanibus, ‘a short-sighted young man, given to empty things’.⁸⁶ Though a tradition which rationalized Drusus Libo’s behaviour as that of a thoughtless young fool had taken hold within a generation, there is sufficient evidence to show that he was not underestimated by those who destroyed him. In the next chapter it will be argued that the treatment of Drusus Libo during and after the investigation was not consistent with the scorn shown to young fools who stumble into trouble, but rather the fear inspired by those who threaten revolution.