On returning from his holiday tour in Egypt, Germanicus found that all his arrangements in Syria had been reversed by Piso, his disposition of the legions had been changed, and his formal alliances with the cities modified. Stormy scenes followed, and Piso decided to leave Syria, so says our narrative; but the more probable order of events is that Piso was ordered by Germanicus to withdraw, and was at Seleucia on his way home when news reached him of the illness of Germanicus. We are not told the nature of this illness. Agrippina and possibly Germanicus himself jumped to the conclusion that poison and spells were the cause of the sickness. Horrible things were found in the house; fragments of human remains embedded in the floors and walls; bits of parchment covered with spells; leaden tablets inscribed with the name of Germanicus, and other mystic apparatus with which it was customary to consign the spirit of an enemy to the shades. The illness seems to have been a lingering one. Piso hovered off the coast, approaching or withdrawing as the symptoms were declared to be better or worse. In the end Germanicus died. Agrippina and her friends were so fully persuaded that he had been the victim of poison or witchcraft, that they exposed his body naked in the market place at Antioch, confident that the flames of the funeral pyre would fail to devour his heart, for it was well known that the heart of a man who had been poisoned was incombustible. When the ceremony was over, Agrippina gathered up the ashes and started with her youngest children for Rome.

Meanwhile the Senators and other officials who had been in the train of Germanicus treated the Province of Syria as though it were vacant, and appointed Gnæus Sentius, one of their number, Governor in the place of Piso. There was no time to send to Rome for orders. Germanicus had cashiered Piso, but had died before appointing his successor, and it was necessary that there should be some one in authority, in case Piso returned and attempted to resume the government of Syria.

Piso had travelled on his homeward journey as far as Cos, when the news of the death of Germanicus reached him. He made thanksgiving offerings to the gods, and Plancina, who had recently lost a sister, threw off her mourning. Consultations were held as to the best course to pursue. Marcus Piso, the younger of his two sons, urged his father to return to Rome. So far he had done nothing unpardonable, but an attempt to resume the government of the province meant nothing less than civil war. Other and less prudent friends advised Piso not to recognize the appointment of Sentius, and to rely on his popularity with the legions. Tacitus puts into the mouth of these advisers the following astounding statement, which he probably found in those memoirs of Agrippina which are not evidence: “You have the complicity of Livia, the favour of Cæsar though hidden, and none mourn more loudly for Germanicus than those who are best pleased at his death.”

Piso and Plancina proved to have miscalculated the affection of the legions, and an attempt to recover Syria by force was defeated by Sentius, who gave the unhappy candidate for power ships and a safe conduct to Rome.

Agrippina meanwhile had traversed the seas and arrived at Brundisium with the vase containing her husband’s ashes early in the year 20 A.D. The illness and death of Germanicus had excited much feeling in the city and Italy, though we are not bound to believe in the dark suggestions of the historian that the populace had assumed the complicity of Tiberius in his nephew’s death. The widow made the best of her affliction, and contrived to give the procession to the Mausoleum of Augustus, in which her husband’s ashes were deposited, the aspect of a public demonstration in favour of the Julian race. Neither Tiberius himself, nor Livia, nor even the mother of Germanicus, were present at this ceremony. Doubtless they had sufficient reasons, but their absence unfortunately favoured the credulity of those who at a later time listened to the lamentations of Agrippina, and her passionate assertions that her husband had been done to death with the connivance of his own kith and kin.

Piso returned slowly to Rome. He sent his son ahead with letters to Tiberius, in which he represented himself as the aggrieved party, and accused Germanicus of debauchery and arrogance; he sought on his way an interview with Drusus, who had returned to Illyria after his brother’s funeral. Drusus received him coldly, and dismissed him with words so politic that they were thought to have been suggested by a cooler head. The day after he arrived in Rome, Fulcinius Trio, the prosecutor of Scribonius Libo, took the first formal steps in a process against him.

The story of this famous trial is so narrated by Tacitus as to convey the impression that there was a serious miscarriage of justice, and that the oppressors of Germanicus were protected by the influence of Livia and Tiberius; but, as usual, the narrative, wherever it depends upon accessible documentary evidence, does not support such a view of the case.

Accusers and accused alike pressed Tiberius to hear the case himself, knowing “that he was impervious to the influence of rumour,” and fearing the excitability of a large court. Tiberius, after hearing the evidence, referred the whole case to the Senate. Five of the most respected men in Rome refused to act as counsel for the defence. Among the three who did eventually defend Piso was Marcus Lepidus, whom we have already seen in possession of the full confidence of the Emperor. On the day of the trial Tiberius opened the proceedings in the Senate; he said that Piso had been a trusted officer and friend of Augustus, that he had himself assigned him as an assistant to Germanicus in the administration of the East with the authority of the Senate. It was the duty of the court to decide without prejudice whether he had exasperated the young man by insubordination and opposition and rejoiced over his death, or had killed him with malice and aforethought, “for if the subordinate officer exceeded the limits of his office, if he refused to pay proper respect to his superior, and rejoiced over his death, and my sorrow, I shall hate him, and shall exclude him from my house, and punish his enmity as a private matter, not with the power I hold as Princeps. But if it is discovered that a crime in bringing about the death of any man requires punishment, then do you confer upon the children of Germanicus and us his relatives our proper consolation. And at the same time you must carefully consider this point, whether Piso handled the armies in an insubordinate and seditious fashion, whether he tampered disloyally with the affections of the soldiers, whether he attempted to recover the province by force of arms, or have the accusers exaggerated these charges? I may say that I have good reason to be annoyed with their exercise of partisanship. For was it proper to strip the body, to expose it to the eager scrutiny of the eyes of the vulgar, and even to allow statements to spread among foreigners that he had been poisoned, if this was still uncertain and a subject of inquiry? I mourn for the loss of my son, and always shall mourn, but I do not prevent the accused from advancing every fact by which his innocence may be supported, or his guilt extenuated if there was any provocation on the part of Germanicus; and I implore you not to take accusations for proved facts, because the case touches me nearly personally. I beg those who have been led by the ties of kindred or faithful friendship to act as counsel for the defendant, to help him in his danger as far as their eloquence and diligence allows; and I invite the prosecution to similar efforts and similar firmness. In one point only we raise Germanicus above the law, viz., in trying the case in the Senate House rather than in the forum, before the Senate and not before a jury. Let everything else be handled with a like moderation. I would have no one pay regard to the tears of Drusus and my own sorrow, nor to any fictitious charges made against us.”

Such a speech was doubtless disappointing to Agrippina, who had already in her own mind condemned Piso and the amazonian Plancina without benefit of clergy; she knew Germanicus had been poisoned, and bewitched; she knew how it had all been done by means of a celebrated poisoner named Martina, who had been fetched from the East to give evidence, and had died mysteriously at Brundisium on the way. Had not the poison been found after her death tied up in her hair? What further evidence was wanting? And why did the woman die so conveniently for the purposes of those who wished to shield the enemies of Germanicus? The poor lady had troubles enough, left a widow with a family of six young children, marked out for the enmity of a malignant and all powerful grandmother-in-law, but her inclination to regard herself as the victim of persistent ill-usage is not evidence; and though her contemporaries would have had no difficulty in believing in the effects of witchcraft, the case against Piso is rendered weak to us by the introduction of this element; and the more so that the prosecution was not able to prove the use of poison, or even to suggest a favourable opportunity for its administration.

As the case proceeded it became quite clear that the charge of poisoning could not be sustained, but that Piso had been guilty of serious political offences. Meanwhile there was considerable agitation among the people, to whom the sensational side of the trial alone appealed, and who threatened violence if the murderer of Germanicus escaped by the votes of the Senate. This at least we are told by Tacitus, though here again it is more than probable that the public excitement existed chiefly in the imagination of Agrippina, who always saw herself playing the part of injured heroine to a sympathetic audience of the Roman people. Riots were not dreaded at Rome since the police of the city had been organized and the Prætorian guards placed in barracks.