The story as it has been handed down to us, so far as it can be collected from fragmentary documents, is to the following effect. Sejanus formed designs upon the succession at a comparatively early period; after the death of Germanicus one man alone, Drusus, stood between him and the object of his ambition. In order to compass the destruction of Drusus, Sejanus, a man certainly past fifty years of age, if not close upon sixty, laid siege to Livilla, the wife of Drusus, the sister of Germanicus. Successful in his assaults upon her not impenetrable chastity, he divorced his wife Apicata, and joined with Livilla and a favourite freedman of Drusus in a conspiracy. Drusus, according to the story, did not die a natural death; he was poisoned by Sejanus through the instrumentality of his favourite Lygdus. The way to the succession now lay clear, for the son of Drusus was still a child, and the eldest sons of Germanicus were little older; moreover, it was supposed that Tiberius disliked the family of Germanicus. To the disappointment of Sejanus, Tiberius showed an inclination to favour this family, and though he sharply reproved the Senate for attempting to confer premature honours upon them, he introduced them to the Senate, and as they advanced in years treated them as his probable successors along with his own grandson.
Sejanus then, we are told, by means of secret emissaries worked upon the excitable temperament of Agrippina in the hope that she would involve herself and her family in ruin by committing some unpardonable offence against Tiberius. In this he was eventually successful, though so long as Tiberius continued to live at Rome the violence of Agrippina was met by somewhat amused contempt. Thus it is recorded that on one occasion Agrippina, goaded by the agents of Sejanus, burst in upon Tiberius when he was sacrificing in presence of the statue of Augustus. The scene is brought home to us if we imagine that the famous statue of the Prima Porta found on the site of Livia’s villa was the statue in question. A friend, and indeed cousin, of Agrippina’s, one Claudia Pulchra, had been accused of unchastity and of magical performances directed against the Emperor himself. It was suggested to Agrippina that she was the person really attacked, and being “always violent,” as Tacitus says, she went straight to the Emperor, and, in allusion to the solemn occupation in which she found him engaged, declared that “a man had no right to offer victims to the sainted Augustus and at the same time persecute his posterity. The divine spirit had not passed into dumb images, but his real presentment, born of his divine blood, understood the inconsistency, and mourned.” She went on to describe the attack upon Claudia as an attack upon herself. Tiberius for once was provoked to a retort, and, quoting a Greek poet, said, “Your only injury, daughter, is that you are not Queen.” This scene in the calm presence of the statue of Augustus was followed by another. Cousin Claudia was found guilty of the offence with which she was charged; but Agrippina persisted in her grievances. She fell into ill-health; Tiberius visited her; she received him at first in silence, then burst into floods of tears. She bewailed her loneliness, and begged him to find her a husband; she was still young, she said; marriage alone would relieve her from the contumelious position in which she found herself; there were plenty of men in the State who would not disdain to welcome the wife and children of Germanicus.
Tiberius left her on this occasion without uttering a word. Then it was suggested to the aggrieved lady by the emissaries of Sejanus that her life was in danger, that poison was being prepared for her, that she should refuse to dine with the Emperor. In consequence, on the next occasion on which she partook of a meal with the head of the family she passed all the dishes, till Tiberius, noting her want of appetite, picked up a particularly fine apple and handed it to her with much praise of its merits; the unhappy lady at once passed the fruit to the slave who stood behind her. Tiberius merely turned to his mother and remarked that it would not be strange if he dealt severely with a woman who accused him of poisoning. This speech led to diverse horrid surmises, but was obviously without any serious purpose, as Agrippina lived unmolested for another five years.
Tacitus tells us that he quoted these details directly from the memoirs of the younger Agrippina, who was possibly present on the last of the three occasions.
After Tiberius had retired to Capreæ the conspirators Sejanus and Livilla were able, we are told, to control the correspondence which was sent to him from the capital. Imprudent remarks made by Agrippina and her sons were carefully reported to him; the provocation which had occasioned them was not reported. The old man was induced to see in the conduct of his great-nephews a repetition of the excesses which had ruined Caius and Lucius Cæsar at the same age. Sejanus fomented discord between the brothers. Drusus the elder was given the office of Prefect of the city; he was encouraged to fear the jealousy of his brother, who was his mother’s favourite. After the death of the aged Livia, Agrippina and her son Nero acted in such a way as to give an opportunity to their enemies; they courted popular favour, and their friends openly advised them to take refuge with the armies on the Rhine, or to take sanctuary with the Senate and invoke the protection of the Roman people. Meanwhile Sejanus had in A.D. 25 formally begged Tiberius to confer upon him the hand of Livilla, the widow of his son Drusus. Tacitus gives what profess to be extracts from the letter which he addressed to the Emperor on the subject, and from the reply which he received. They are to the following effect. Sejanus is represented to have said that “he had become so habituated to the kindness of Augustus, and then by many proofs to that of Tiberius, as to address his hopes and prayers to the ears of the Princes as soon as to the gods. He had never asked for brilliant office, he preferred to share with the common soldiers the toils of guarding the Emperor. Still he had obtained what he thought most honourable, he was thought worthy of association with Cæsar. On this his hopes were founded. And as he heard that Augustus had once taken into consideration the claims of Roman knights when he was thinking about placing his daughter, so he begged Tiberius, if a husband were sought for Livilla, to remember a friend who would be content with the mere honour of relationship. He did not wish to be relieved of the duties which had been imposed upon him; he thought it sufficient that the family should be strengthened against the malicious persecutions of Agrippina, and that for the sake of the children. For himself the life which he had already lived with such a Prince would be much and more than enough.”
The genuineness of this document is certainly open to suspicion. It is notorious that Tiberius particularly disliked any form of address or exaggerated respect which put him on a level with the gods; nor could Sejanus have openly alluded to the extravagances of Agrippina without running the risk of incurring a smart rebuff, unless indeed he were already on such familiar terms with the Emperor that his previous humiliation of himself was unnecessary. The document has probably passed through the crucible of Agrippina’s memoirs. The reply attributed to Tiberius, though not beyond suspicion, has a more genuine note, and resembles other speeches and documents of the same author in its general character. The Emperor began with commending the loyal affection of Sejanus, and, after demanding time for full consideration, added that whereas other men have to think only of what is conducive to their own interests, Princes must think before all things of their reputation; and therefore he did not reply, as it was simple to do, that Livilla could decide for herself whether she would take another husband in succession to Drusus or would continue to live in the same house, that she had her mother and grandmother, her nearer advisers. He would deal more plainly. In the first place, there was the question of the animosity of Agrippina, which would be far more violent if the marriage of Livilla set the house of the Cæsars at variance. Even as things were, the rivalries of the women occasionally broke out, and his grandchildren were the victims of these discords. What if the rivalry were rendered more intense by such a marriage? “For you are mistaken, Sejanus, if you think that you will remain in the same rank, and that Livilla, who has been the wife of Caius Cæsar and then of Drusus, will be content to grow old with a mere Roman knight. Even though I should permit it, do you think that it would be allowed by those who have seen her brother, her father, and our ancestors in the very highest offices? You indeed are willing to stay in your present station; but those magistrates and nobles who break through to me against your will, and consult with me on every question, say without any concealment that you have already long ago passed beyond the highest Equestrian dignity, and gone far in advance of the friendship which my father showed you, and in consequence of their envy of you I too am blamed. But you say Augustus thought about conferring his daughter’s hand on a Roman knight. Surely we have no reason to be surprised that when Augustus was distracted by every kind of anxiety, and foresaw that the man whom he should raise above others by such a match was immeasurably exalted, he did discuss the claims of Gaius Proculeius and some others of noted tranquillity of life, and in no way concerned with the business of the State. And if we are affected by the hesitation of Augustus, how much stronger an argument is the fact that he did place her with Marcus Agrippa and then with myself? In consideration of our friendship, I have not thought it right to conceal these considerations; however, I will not stand in the way of what you and Livilla propose. I will omit for the present to refer to some plans that I have formed, and to tell you the ties by which I propose to associate you with myself. I will only disclose this, that there is no position so lofty that it is not deserved by your virtues and your disposition towards myself; and when the opportunity comes, I will speak openly in the Senate, or in a public address.”
Even in this letter there are suspicious passages. Tiberius could hardly have spoken of the magistrates who broke into him against the will of Sejanus without an admission of weakness, which is almost incredible, unless we are to assume that he wished to snub Sejanus, an assumption, however, which is not supported by the conclusion of the letter. Nor was this letter a public document, preserved in the public records; if preserved at all, it was among the family papers.
One important hint we get from this letter: its writer or editor ranges Livilla and her child in opposition to Agrippina and her children, and saw in the possible marriage with Sejanus a strengthening of the children of Drusus against the children of Germanicus. A similar protection had been given thirty-six years previously to the children of Julia, when Tiberius was made their stepfather. Livilla never married Sejanus, but her attempt to marry him supplies a clue to the labyrinth of plots in the Imperial household. If the principle of heredity was to be recognized, the heirs to the throne were Livilla’s son, the younger Tiberius, and Agrippina’s sons, the former representing the Claudians, the latter the Julians, and the situation was repeated which had existed when Tiberius and his brother had represented the Claudians, Caius and Lucius Cæsar the Julians.
Livilla, anxious for the safety of her son and eager to promote his interests, endeavoured to fasten herself to the strongest man in the State, who would unquestionably on the decease of Tiberius be in possession of the controlling military power.
According to the accepted story, there was a guilty connexion between Sejanus and Livilla before the death of her husband, and Sejanus had divorced his wife at the request of his paramour; the two together had poisoned Drusus.