Roman history is filled to the brim with fascinating characters. However, there is an almost unknown
intriguer who managed to gain immense political power, and almost ascended into imperial purple
himself - Lucius Aelius Sejanus, the Praetorian Prefect under Tiberius. Under his jurisdiction,
the Praetorian Guard became one of the most powerful institutions in Roman society, and
it would set the tone for centuries of ambition and intrigue. Welcome to our video on Sejanus
in the the Roman Principate.
Augustus’ reforms made the rise of the Praetorian Guard possible. Seeing the chaos caused by
the legions in Italy during the Late Republic, Augustus garrisoned them permanently in the
provinces. This was nominally to ensure compliance among the conquered peoples, and to put down
any rebellions, but it also served to cut out the outright sense of military dictatorship
which had plagued the pre-Augustan era. To replace the legions, another institution was
formed, the cohortes praetoria. By the time of the death of Augustus in 14
AD, the established praetorians were commanded by two men of equestrian status: the father
and son duo of Lucius Seius Strabo, and Lucius Aelius Sejanus. Sejanus was born in the Etrurian
city of Vulsinii and had reportedly accompanied the young Augustan heir-apparent Gaius Caesar,
grandson of Augustus, to the east as a young man, as his family had impressive political
connections. They were related to the consular Terentii house, and through the father’s
extensive marital family had a number of consular step-relatives, including the governor of
Pannonia, Junius Blaesus. All of this would naturally have enhanced
the young Sejanus’ future career prospects. The death of Augustus had triggered a mutiny
among Blaesus’ legions in Pannonia, as suspended normal military routines led to a breakdown
in discipline. When this news reached the successor - Tiberius,
he sent his son, Drusus the Younger, with two praetorian cohorts, in order to quell
the revolt. On the way, they were joined by some praetorian cavalry and German bodyguards.
This was the first attested use of the imperial guard in the field, and Sejanus was present.
He was sent so that he could watch over the Drusus, a mark of his already substantial
influence over Tiberius. In 15 AD, Sejanus’ father and co-prefect,
was appointed to the most prestigious post open to any equestrian - the praefectus Aegypti,
the prefect or governor of Egypt, which was the Emperor’s personal province. This left
Sejanus as the guard’s sole commander, and his influence continued to rise throughout
the years. In 21 AD a new governor of Africa was required
and Sejanus used his influence to get his uncle the appointment. A year later, the massive
theatre built by Pompey Magnus burst into flames. This would have been a catastrophe,
but for the swift actions of Sejanus and his praetorians. They were quickly sent to douse
the inferno, an action which saved the city from the spreading flames, but not the illustrious
venue. Tiberius heaped praise upon him, and the senate voted that a statue be erected
for his deeds. Sejanus proved his cruelty by ordering the lone dissenting senator’s
assassination a few years later. Despite Sejanus’ increasing influence, Tiberius
was unconcerned. Why? How had Sejanus managed to make such a strong impression on the Emperor?
By the middle of his reign, Tiberius was in his mid-sixties and had lost many of his friends.
This left the generally distrustful Princeps isolated, and he became reliant on the praetorian
prefect, whom he did trust. Sejanus was viewed as a loyal servant of Rome,
but unlike other courtiers was not sycophantic. He was seen as an efficient administrator
and commander with an independent mind. His lower equestrian status may also have helped
him, as emperors were often suspicious of ambitious senators. Tiberius surrounded himself
with equestrians, including Sejanus, who were viewed as less of a political threat.
Nevertheless, in 23 AD Sejanus made his first significant move to increase his power and
the political potential of the praetorian guard - a move which would have consequences
for the next three centuries of imperial rule. He took the apparently pragmatic step of installing
and concentrating all the praetorian cohorts into the newly finished Castra Praetoria - the
vast praetorian camp complex, which was surrounded by walls similar to the legionary fortresses.
Before, the praetorians been scattered throughout Italy, or in the vicinity of Rome. It may
have increased the effectiveness and cohesion of the guard, but it also made the praetorians
more influential. The nature of Sejanus’ ambitions were unclear
at this point, but it seems that initially his aim was to isolate and dominate Tiberius.
Ultimately, it is widely speculated that he wished to marry into the imperial family and
even perhaps to become the Emperor’s logical successor. There was one key obstacle to the
devious plans of Sejanus - Tiberius’ trueborn son, Drusus.
Even though the two had worked together in the past, there was significant animosity
between them. Drusus bitterly resented the fact that the ‘upstart’ Sejanus was now
regarded as Tiberius’ ‘partner in labours’ and made no attempt to conceal his dislike,
even attempting to strike Sejanus on the cheek after the rivals had once argued. Meanwhile,
Sejanus likely earned this dislike through his intrigue and the attempted political marginalisation
of Tiberius’ son. This would all soon come to a head. In order
to surmount his dynastic obstacle, Sejanus reportedly seduced the wife of Drusus – Livilla.
Her reasonings for embarking on this affair with the praetorian prefect are not known,
but it is likely that she either wanted to protect the imperial interests of her sons,
that she was sick of her husband’s apparently violent temper, or that she was possibly just
in love with Sejanus. Whatever the case, Sejanus realised he had
to act soon. The shared consulship and the grant of tribunician power by Tiberius upon
Drusus did not merely mark him as the successor. It also suggested that Tiberius, who had never
liked being Emperor, was soon to retire, and would leave his son to rule instead. If Drusus
was allowed to succeed, the career of the prefect and perhaps even his life, might come
to an untimely and violent end. Sejanus decided to use Livilla, who was now
firmly under his influence, to form a conspiracy to kill Drusus. A poison was chosen, the symptoms
of which could be easily passed off as disease. In early September of 23 AD, Drusus’ wine
taster administered the draught. Drusus became gradually sicklier for several days, then
passed away. Tiberius was devastated by his son’s death, but remained convinced for
years that his son had died from ill-health. The first stage of Sejanus’ grand design
had been successfully accomplished. The path to power seemed open for him, as
the brother of Germanicus, Claudius, was physically and mentally ailed, while his sons were too
young to rule. However, they all were of the imperial bloodline, while Sejanus was not.
Acting accordingly, his next target was Agrippina, the widow of Germanicus since his death in
19 AD. He sought to isolate her by picking off her allies. Her influence was supposedly
significant, especially among the former Rhine legions of her revered late husband, and it
is said that she held more influence than the legates themselves.
Agrippina was convinced that the adopted Tiberius had conspired to kill her true-blooded husband
and therefore wished for her sons to rule; it was this that initially caused hostility
between the two. Sejanus whispered into the ear of Tiberius, arguing that the supposed
partium Agrippinae - Agrippina’s faction - was treacherous and threatened his rule.
So, with the Emperor’s blessing, he set to cutting them down to size.
His first target was Caius Silius, a respected senator and the commander of an army in Germania,
who had bragged that if not for him, Tiberius would have been ousted during the mutiny at
the beginning of his reign. Sejanus had him arrested on trumped up charges of treason.
The prefect had made it seem as if it was Tiberius attacking Agrippina and her supporters.
Further proscriptions followed, and Sejanus’ grew ever bolder. He realised that being praetorian
prefect allowed him to destroy whomever he so wished, if he had the emperor’s unwavering
trust. He became so powerful, that falling out with
him was a death sentence. Buoyed by his climbing of the ladder of power thus far, he composed
a notorious letter to Tiberius in 25 AD, requesting a formal marriage to Livilla - with whom he
had been having an affair for years. In this letter, he recalled the benefits heaped upon
him by Tiberius and Augustus before him, but that he had never sought the splendour of
high office. He deemed it sufficient a reward to serve such a master as Tiberius. Instead,
the fairest honour he could hope for was a marriage tie to the House of the Princeps.
He even hinted that Augustus himself had considered an equestrian for marriage to his own daughter,
an attempt at harkening back to the past to impress his Emperor.
The letter gives a truly fascinating insight into the political skill of Sejanus and the
extent of his ambition, which seemed to be at this point to integrate himself into the
dynasty. Though the letter was intelligent, Sejanus had overstepped his bounds, and received
a warning letter from Tiberius, writing that the senators were already complaining about
his lofty status for a man of equestrian rank. Apparently alarmed by the revelation that
he had increasing amounts of enemies in high places, Sejanus now began to encourage Tiberius
to withdraw from the center of government. The Emperor was never truly eager for the
position and had withdrawn from politics several times before.
In 27 AD, Tiberius journeyed through Campania to the secure island of Capri, where he would
not be disturbed. He even enacted a law forbidding anyone from disturbing his quiet. Though historian
Tacitus gives us a number of reasons for the withdrawal to Capri, he cites the constant
intrigues of Sejanus as the main factor, as he would constantly stoke mutual distrust
amongst Tiberius and his family, even going so far as to convince the princeps they wanted
to poison him. It was at this time that another coincidence
occurred which happened to show why Tiberius trusted Sejanus so much. At a key moment,
when his party were dining in a cave-restaurant near Naples, a rockfall almost killed the
Emperor, but Sejanus managed to save him. On the remote island of Capri, the praetorians
controlled access to Tiberius completely. The prefect also ordered spies to keep an
eye on Agrippina and her family. In absence of Tiberius, the power of Sejanus in the capital
was unchallenged. His authority even extended to approving the candidates for Consulship.
Attempting to secure his power further, he now attacked Tiberius’ most likely successor:
Nero Julius Caesar, the son of Agrippina and Germanicus. Sejanus’ agents and accomplices
brought false accusations against him, which were made believable by Nero’s often ill-advised
behavior. His indiscreet remarks or complaints were exaggerated and reported to the isolated
Tiberius on Capri, who was enraged at his adopted grandson’s apparent brazenness.
Sejanus, who actually still masqueraded as an ally of the matriarch, advised her and
Nero to take refuge with her trusted Rhine legions. However, this was a trick, which
made Tiberius even more paranoid. In an attempt to widen existing divisions,
the prefect tempted the greed and jealousy of Nero’s younger brother, another Drusus,
by hinting that he might gain the principate for himself due to his brother’s actions.
The praetorian then did what he had to the original Drusus, and enlisted his wife to
turn on him. These schemes paid off. The younger Drusus was locked in prison, while Nero was
exiled to Pontia and forced to commit suicide in 31 AD.
The praetorian prefect could hardly rise any higher. He was supreme - the open partner
of Tiberius’ labours as his consular colleague, and equally feared and fawned upon even by
those who most hated him. However, before the year was out, Sejanus and his family were
dead, his statues destroyed and his name erased from the public record. Again, we must ask
why? Tiberius himself professed that the punishment
of his former favourite was due to the revealed plots against the children of Germanicus,
but some historians reject this as an excuse. It was possible that there was a conspiracy
of murder against Tiberius himself. This is given further credence by Sejanus’ negotiations
with the German legions, who would likely support him if Tiberius were to perish. It
is even possible that the murder of Drusus the Younger in 23 had been uncovered. Whatever
the case, in mid-31 AD, Sejanus received an abrupt letter of denunciation in the senate,
and was dragged off and unceremoniously murdered by his former subordinates. His family and
acquaintances suffered equally afterwards, and a witch hunt for those he associated with
resulted in many deaths, including Livilla who was starved to death.
The legacy of this extraordinary figure was widespread fear among the senatorial class
and their accelerated sycophancy. Tiberius ruled until 37 AD, but never recovered from
the blows inflicted by Sejanus. His destruction of Drusus the Younger in 23 and Nero Julius
Caesar in 31 eventually had an unforeseen long-term consequence, leading to the ascension
of one of the most insane emperors in history: Caligula - the sole male survivor of Sejanus’
inquisition.
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