Schol. on Iuv. 5, 105, ‘Revocatus ... etsi magno desiderio Athenas intenderet ab Agrippina tamen in palatium adductus.’
Dio, lxi. 10, 1, οὐ γὰρ ἀπέχρῃσεν αὐτῷ τὴν Ἰουλίαν μοιχεῦσαι, οὐδὲ βελτίων ἐκ τῆς φυγῆς ἐγένετο, ἀλλὰ καὶ τῇ Ἀγριππίνῃ ἐπλῃσίαζεν.
For Seneca’s tutorship cf. also Sueton. Nero, 52, ‘Liberales disciplinas omnes fere puer attigit. Sed a philosophia eum mater avertit, monens imperaturo contrariam esse: a cognitione veterum oratorum Seneca praeceptor, quo diutius in admiratione sui detineret.’
It is probable that Seneca was, like Nero, privy to the murder of Claudius in A.D. 54. Cf. his sarcasms against Claudius in his Apocolocyntosis.
Sueton. Nero 33 (of Nero), ‘Cuius [Claudi] necis etsi non auctor, at conscius fuit: neque dissimulanter, ut qui boletos, in quo cibi genere venenum is acceperat, quasi deorum cibum, posthac proverbio Graeco conlaudare sit solitus.’
Seneca wrote for Nero a speech which he delivered on the occasion of Claudius’ death.
Tac. Ann. xiii. 3, ‘Die funeris laudationem eius princeps exorsus est; dum antiquitatem generis, consulatus ac triumphos maiorum enumerabat, intentus ipse et ceteri; liberalium quoque artium commemoratio, et nihil regente eo triste rei publicae ab externis accidisse, pronis animis audita. Postquam ad providentiam sapientiamque flexit, nemo risui temperare, quamquam oratio a Seneca composita multum cultus praeferret, ut fuit illi viro ingenium amoenum et temporis eius auribus accommodatum.’
He acted as a check on Nero (Tac. Ann. xiii. 6; 11), and baffled Agrippina’s vengeance and ambition.
Tac. Ann. xiii. 2, ‘Ibaturque in caedes, nisi Afranius Burrus et Annaeus Seneca obviam issent. (Ch. 5) Quin et legatis Armeniorum causam gentis apud Neronem orantibus escendere suggestum imperatoris et praesidere simul parabat, nisi ceteris pavore defixis Seneca admonuisset, venienti matri occurreret.’
Seneca interfered to shelter Nero in his amour with Acte, A.D. 55, and used the occasion to stir up feud between Agrippina and Nero (Tac. Ann. xiii. 13). Hence followed an attack by Agrippina on Seneca.