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Sejanus as Partner in Power

The Pinnacle of Power

Perhaps in 25, Sejanus suggested that he marry Drusus’ widow, Livilla, whose bed he possibly already shared (Annales 4.39). Tiberius refused the marriage (Annales 4.40). Tacitus has, seemingly, extensive documentation of the discussion. We might expect that such matters were discussed in darkened corners and secret whispers, but the proposal was made in writing and the refusal was similarly documented. It seems possible that these documents were later published.

Tiberius’ reply, as reported, is a masterpiece:

  1. Livilla can do as she wants and seek advice from the senior women of the imperial household (it is not really Tiberius’ decision, but…)
  2. Agrippina will see it as dividing the imperial family into two warring factions (though how could Tiberius himself think that?)
  3. You are not ambitious (really?), but Livilla is and would press for your elevation (which would be unfortunate), and the hypocritical senators who fawn on you also complain that you are too mighty and ambitious and they will come to believe it even more (and what if Tiberius were to listen to the complaints?).
  4. Augustus may have have thought of marrying his daughter off to an eques, but he was tired and over-stressed, and when it came to it, her married her to Agrippa and Tiberius (partners in power and former consuls). Implicit here is either the suggestion the Sejanus is not good enough or that the marriage would make him the equivalent to Agrippa or Tiberius himself.
  5. He will not oppose the marriage (but not bless it either and what might be the consequences of flouting Tiberius’ advice?).
  6. There are other ways of rewarding Sejanus through official means.

The letter was a refusal, but Sejanus did not give up on his ambitions.

In AD 28, the senators voted altars to Amicitia (Friendship) and Clementia (Mercy). Clementia was an imperial virtue, since it was the emperor who exercised mercy. Statues of Tiberius and Sejanus adorned the sanctuary (Annales 4.74).

With the fall of Agrippina and her boys in AD 29, Sejanus’ position seemed assured. He was named as consul for 31 BC. Tiberius was to hold the consulship with him. This was an honour normally reserved for members of the imperial family. The expectation must have been that this was a preliminary to some sort of more formal acknowledgement of Sejanus as partner in the imperial position. Bronze statues were constructed to Sejanus and Tiberius. Gold chairs were made for both men for the theatre. Sacrifices to the gods for Tiberius were replicated by sacrifices for Sejanus (Dio, 58.4).


There is a question as to Sejanus’ marital situation. Apicata was the mother of his children, whom he divorced probably around AD 23. He was thought to be Livilla’s lover. A fragment of Dio suggests Sejanus married Livia Julia, daughter of Livilla and Drusus (Dio, 58.3.9). He was certainly betrothed (Dio, 58.6). Tacitus reports (or invents) a speech in which an about-to-be condemned friend of Sejanus claims that though he is guilty because of his friendship, the emperor is innocent in spite of him making Sejanus his ‘son-in-law’. This would seem to point to a marriage, which can only be in 30 or 31. But it is curious that Sejanus did not marry Livilla and that there is not more explicit mention in the sources (Annales, 5.6). The marriage would have confirmed Sejanus’ place at the heart of the imperial family.

Why Sejanus?

One of the key questions is why Tiberius raised Sejanus so high.

The emperor had many possible advisers, including member of his family. It seems odd to bring in an outsider.

Reference is sometimes made to his status as an equestrian. Tiberius refers to it in his document refusing marriage to Livilla. Tacitus also refers to it in reference to his seduction of Livilla (Annales 4.2) calls him a ‘small-town adulterer’. The contrast is with Livilla’s high status and that of her previous husbands.

  • Was Sejanus regarded as an upstart?

The praetorian prefect was always an equestrian, from the second rank of the Roman aristocracy. He had certainly not the long-ancestry of others in the Roman elite. But many perfectly respectable individuals achieved high status without social snobbery being obvious. These included men like Tacitus, his father-in-law Agricola, and, indeed, the Younger Pliny. Tiberius compared him unfavourably with Agrippa, but Agrippa’s family were considerably less prominent than that of Sejanus. Through adoption, he was connected to leading families. He was not an outsider. Moderns tend to think that the emphasis in the insult should be put on ‘small-town’ (thinking about class), but ‘adulterer’ was more damning in Roman eyes (thinking about morality).

  • Socius Laborum

With power concentrated on the emperor, the emperor needed help. Augustus had had a succession of individuals close to him on whom he could rely. Later emperors were to do the same. Someone like Sejanus was necessary. First ministers are very useful for absolute monarchs. They do all the hard work, make all the deals, and set the direction. Moreover, a first minister is expendable and can be blamed if it all goes wrong.

  • The loyal servant

The benefit of having a first minister of relatively low status is that the minister can never be a threat: they cannot assume the imperial position themselves and they need the monarch to continue to rule so that their own power is maintained. If you appoint someone of too low a status, the aristocracy hate them and will not do what they are told. They might also hate the monarch for appointing such a low figure ‘over’ them. The French monarchs solved the dilemma by appointing priests, persons disqualified from the throne. Byzantines (and others) used eunuchs. Tiberius used his praetorian prefects.

The Sejanus Dilemma

Sejanus was an ideal servant for Tiberius so long as he could not challenge the emperor or succeed him. Sejanus’ power was that he could be seen to act for the emperor. Sejanus’ weakness was that he could not succeed to the imperial position: imperial heirs would always threaten his position and so the aristocracy could look forward to the moment of his fall. In the long term, Sejanus could only become secure if he could line himself up for the imperial position. But as soon as he achieved that, he ceased to be the loyal servant and the expendable first minister. If Tiberius started to think Sejanus was in charge, not him, then Sejanus was vulnerable.

The evidence is overwhelming. Tiberius was grooming Sejanus as a successor in some form to the imperial power. He even starts to appear on provincial coinage. But it is that coinage which provides some of the most dramatic evidence of Sejanus’ fall .

Tiberius changed his mind. The consequences were brutal.


Fall of Agrippina                                                                                    Death of Sejanus


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