Nero's removal of the descendants of Augustus meant that the option to replace him was extended to others whose connexion with the Caesars was far more distant. Nero's unpopularity was exploited by a group of people who selected as their candidate C. Calpurnius Piso, the man whose marriage to Livia Orestilla had been barred by Caligula (see above, p.226); Claudius had recalled him from exile and gave him a consulship in 41. The members of the conspiracy were said to have included Faenius Rufus, co-prefect of the guard, who was afraid of the influence of Tigellinus, with three of the sixteen praetorian tribunes. The consul designate, Plautius Lateranus, was also involved, and many others were accused. To give legitimacy to the cause, Claudius' daughter Antonia was to be taken to the praetorian camp after Nero had been killed in the circus. There was nothing 'republican' about the plot.
The effect of the conspiracy was that Nero now became afraid of many who were not related to him; and he reacted by eliminating an extraordinary number of suspects. Seneca was one of those required to end their lives. Donatives were given to the praetorian guard, and other gifts to those Nero thought he could continue to trust: triumphal insignia to Tigellinus, Petronius Turpilianus, and the later emperor Cocceius Nerva. Nymphidius Sabinus, grandson of Caligula's freedman Callistus, was given insignia consularia, and appointed praetorian prefect in association with Tigellinus. Nero may have had doubts as to whether Tigellinus was as efficient a soldier as he had been a horse-breeder.
The death of Poppaea Sabina in a.d. 65 was a political as well as a personal disaster for Nero: she had not provided him with an heir.54 There were rumours of further plots, and executions. C. Cassius Longinus, husband of Iunia Lepida, was forbidden from attending meetings of the Senate; soon after Nero asked the Senate to exile him and his wife's nephew Lucius Iunius Silanus. Silanus, son of the Marcus reputedly poisoned by Agrippina in 54, was a descendant of Augustus; although the Pisonian conspirators had ignored his prior claim to the position of Caesar, Nero felt he had to execute him after a trial for incest. Cassius himself was able to return from exile in Sardinia under Galba. Another casualty of a distant relationship with the imperial family was
Antistius Vetus, Rubellius Plautius' father-in-law, and once a protege of Agrippina.
Nero's execution of those he feared continued into 66. Ostorius Scapula, son of an early governor of Britain, had consulted astrologers about how much longer Nero was likely to survive. P. Anteius, an ex- consul, was accused on the same charge; both killed themselves. The list of casualties included Seneca's two brothers, Annaeus Mela (father of Lucan, who had already killed himself on Nero's orders), and Gallio (who appears in the Acts of the Apostles as governor of Achaea); C. Petronius, Tigellinus' rival as Nero's boon companion; the ex- praetorian prefect Rufrius Crispinus; Anicius Cerealis, who had been consul in 65; and the two noted Stoics, Thrasea Paetus and Barea Soranus. Stoicism may have given some of these the vocabulary and slogans to articulate their opposition to the way Nero was behaving, but those Roman families that now turned against Nero did not do so as a 'group' or 'party', nor, primarily, because of any philosophical beliefs they may have held about 'ideal kingship', let alone 'republicanism'.
To strengthen his own dynastic position, Nero proposed to marry Claudius' daughter Antonia; but she had no wish to oblige. Instead, Nero married Statilia Messallina, the widow of another of his victims, Vestinus Atticus. She counted amongst her ancestors Augustus' generals Statilius Taurus and Valerius Messalla Corvinus.
Nero also made every effort to re-establish his military prestige after 65. He made the most of the solution to the Armenian problem which had been achieved by Corbulo, and arranged some spectacular festivals on the occasion of King Tiridates' visit to Rome in 66 to receive his diadem from Nero's own hands. New issues of coins stressed 'Augustan Victory', the Altar of Peace, and the fact that 'he shut the temple of Janus after peace had been achieved by land and sea'. Nero honoured generals like Vespasian and Suetonius Paulinus (who was granted a second consulship), perhaps to counter any threat from the virtus demonstrated by Corbulo. And he planned to gain military prestige himself by leading a major expedition in the East during these years; it was a period when both the Romans (on the lower Danube) and the Parthians felt that they were coming under increasing pressure from tribes originating further east (the legate of Moesia between a.d. 60 and 67, Tiberius Plautius Silvanus, had already been involved in fighting). The good relations between Nero (and later Vespasian) and the Parthians suggest that in the context of the solution to the Armenian conflict, the two states had come to an agreement about the need for military co-operation. Nero advertised an expedition against the 'Caspian Gates' at the eastern end of the Caucasus, and astrologers predicted that he would be enthroned in glory at Jerusalem. In preparation for the campaign, the Fourteenth Legion was withdrawn from Britain; it had distinguished itself in the repression of Boudica, and was granted the title Martia Victrix. Turpilianus (one man Nero trusted) was put in charge of raising a new legion in Italy. The annexation of Pontus as a province in a.d. 64 may also have been connected with Nero's eastern plans. The coins struck during his last years reveal an increasing interest in military matters.55 But Nero's prime concern apparently continued to be the glory he could achieve as a public performer. Only the Greeks, he was heard to say, appreciated real virtue. He may originally have wanted to visit Greece in a.d. 6 5, to be able to compete at the regular Olympic games. In the event, certain quadrennial games had to be rescheduled in order to allow him to participate, and carry off the prizes. It is clear that his visit made him genuinely popular in Greece. At Corinth, he dramatically re- enacted the 'liberation' of Greece from direct Roman administration, as played out by Flamininus in 196 b.c. 56
During Nero's journey to Greece with his entourage, a further conspiracy was uncovered at Beneventum (details are sparse, and it is not clear whether Nero was present when the conspiracy was brought to light). The leading figure was Annius Vinicianus, who was executed. Nor is it clear what this man's relationship was to the Annius Vinicianus who was involved in Camillus Scribonianus' rebellion against Claudius: his brother may have been the Annius Pollio implicated in the Pisonian conspiracy in the previous year. What is known is that he was Corbulo's principal supporter. He had been legatus of the Fifth Legion in Corbulo's Armenian campaign of c. a.d. 58, and was the husband of one of Corbulo's two daughters (the other was later to become Domitian's wife). In the previous year, Annius had been sent by Corbulo to accompany Tiridates on his journey to Rome; Cassius Dio says that this was as much to put a hostage of his good faith into Nero's hands as anything else. Tiridates had commented to Nero 'What a good slave he had in Corbulo'. The conspiracy at Beneventum - whether real or imagined - meant that Nero knew that he could now no longer rely on Corbulo's support. The implication was clear, and Corbulo was summoned to meet Nero in Greece, where he was ordered to kill himself. A little later (and presumably in connexion with the same conspiracy) the legates of the upper and lower Rhine armies were also summoned to Nero in Greece, and forced to suicide. They were the brothers Publius Sulpicius Scribonius Proculus and Scribonius Rufus, sons of a senator