Insisting on wanting to make a Roman of this young debauché, Agrippina made him into a murderer. Nero, progressing from one caprice to another, finally imagined a great folly: to divorce Octavia and to raise to her place a beautiful freed-woman called Acte. According to one of the fundamental laws of the State, the great law of Augustus on marriage, which forbade marriages between senators and freedwomen, the union of Nero and Acte could be only a concubinage. Agrippina wanted to avoid this scandal; and, as Nero persisted in his idea, it seems that she actually thought of having him deposed and of securing the choice of Britannicus, a very serious young man, as his successor. A true Roman, Agrippina was ready to sacrifice her son for the sake of the Republic.
The threat was, or appeared to be, so serious to Nero, that it made him step over the threshold of crime. One day during a great dinner to which he had been invited by Nero, Britannicus was suddenly seized with violent convulsions. "It is an attack of epilepsy," said Nero calmly, giving orders to his slaves to remove Britannicus and care for him. The young man died in a few hours and every one believed that Nero had poisoned him.
This dastardly crime aroused at first a sense of horror and fright among the people, but the impression did not last long. In spite of all his faults, Nero was liked. In Rome they had respected Augustus and hated Tiberius; they had killed Caligula and jeered at Claudius; Nero seemed to be the first of the Roman Emperors who stood a chance of becoming popular. Contrary to Agrippina's ideas, it was his frivolity that pleased the great masses, because this frivolity corresponded to the slow but progressive decay of the old Roman virtues in them. They expected from Nero a less hard, less severe, less parsimonious government—in a word, a government less Roman than the rule of his predecessors, a government which, instead of force, glory, and wisdom, meant pleasure and ease.
So it happened that many soon forgot the unfortunate Britannicus, and some even tried to justify Nero by invoking State necessity. Agrippina alone remained the object of the universal hatred, as the sole cause of so many misfortunes. Implacable enemies, concealed in the shadow, were subtly at work against her; they organised a campaign of absurd calumnies in the Court itself, and it is this campaign from which Tacitus drew his material.
Some wretches finally dared even accuse her of conspiracy against the life of her son. Agrippina, refusing to plead for herself, still weathered the storm, because Nero was afraid of her, and though he tried to escape from her authority, did not dare to initiate any energetic move against her. To engage in a final struggle with so indomitable a woman, another woman was necessary. This woman was Poppæa Sabina, a very handsome and able dame of the great Roman nobility. Poppæa represented Oriental feminism in its most dangerous form: a woman completely demoralised by luxury, elegance, society life, and voluptuousness, who eluded all her duties toward the species in order to enjoy and make others enjoy her beauty.
Corrupted as that age was, Poppæa was more corrupt. As soon as she observed the strong impression she had made on Nero, she conceived the plan of becoming his wife; her beauty would then be admired by the whole Empire, would be surrounded by a luxury for which the means of her husband were not sufficient, and with which no other Roman dame could compete. There was one obstacle—Agrippina.
Agrippina protected Octavia, a true Roman woman, simple and honest: Agrippina would never consent to this absolutely unjustifiable divorce. To force Nero to a decisive move against his mother, Poppæa had her husband sent on some mission to Lusitania and became the mistress of the Emperor. From that point the situation changed. Dominated by Poppæa's influence, Nero found the courage to force Agrippina to abandon his palace and seek refuge in Antony's house; he took from her the privilege of Prætorian guards, which he himself had granted her; he reduced to a minimum the number and time of his visits, and carefully avoided being left alone with her. Agrippina's influence, to the general satisfaction, rapidly declined, while Nero gained every day in popularity. Agrippina, however, was too energetic a woman peaceably to resign herself: she began a violent campaign against the two adulterers, which deeply troubled the public. In Rome, where Augustus had promulgated his stern law against adultery; in Rome, where Augustus himself had been obliged to submit to his own law, when he exiled his daughter and his grand-daughter and almost exterminated the whole family; in Rome, a young man of twenty-two dared all but officially introduce adultery and polygamy into the Palatine! In her struggle against Nero, Agrippina once more stood on tradition: and Nero was afraid.
Poppæa was probably the one who suggested to Nero the idea of killing Agrippina. The idea had been, as it were, floating in the air for a long time, because Agrippina was embarrassing to many persons and interests. It was chiefly the party that wanted to sack the imperial budget, to introduce the finance of great expenditure, which could not tolerate this clever and energetic woman, who was so faithful to the great traditions of Augustus and Tiberius, who could neither be frightened nor corrupted. One should not consider the assassination of Agrippina as a simple personal crime of Nero, as the result of his and Poppæa's quarrels with his mother. This crime, besides personal causes, had a political origin. Nero would never have dared commit such a misdeed, in the eyes of the Roman almost a sacrilege, if he had not been encouraged by Agrippina's unpopularity, by the violent hatred of so many against his mother.
Nero hesitated long; he decided only when his freedman, Anicetus, the commander of the fleet, proposed a plan that seemed to guarantee secrecy for the crime: to have a ship built with a concealed trap. It was the spring of the year 59 A.D.; the Court had moved to Baiæ, on the Gulf of Naples. If Nero succeeded in getting his mother on board the vessel, Anicetus would take upon himself the task of burying quickly below the waves the secret of her death; the people who hated Agrippina would easily be satisfied with the explanations to be given them.
Nero executed his part of the plan in perfect cold-blood. He made believe he had repented and was anxious for a reconciliation with his mother; he invited her to Baiæ and so profusely lavished kindnesses and amiabilities upon her, that Agrippina finally believed in his sincerity.