D. ad 31,
of Volsinii (mod. Bolsena). Sejanus’ father was an eques (knight), Lucius Seius Strabo, his mother the sister of Quintus Iunius Blaesus, suffect consul ad 10, and connected with Aelii Tuberones and Cassii Longini. Sejanus, who had attended Augustus’ grandson Gaius in the east, was made Strabo’s colleague as prefect of the guard by Tiberius in ad 14, and soon, on his father's appointment as prefect of Egypt, became sole commander; by 23 he had concentrated the guard in barracks near the porta Viminalis. After the death of Tiberius’ son Drusus in 23 (murder was later imputed) his influence was paramount; a succession of prosecutions eliminated opponents (chiefly adherents of the elder Agrippina). Tiberius allegedly refused to allow a marriage with Drusus’ widow Livia Julia (25), but retired from Rome in 26, further increasing Sejanus' influence (he allegedly encouraged the move); honours and oaths were offered to him as to Tiberius. In 29 Agrippina and her eldest son Nero Julius Caesar were deported; her second, Drusus Julius Caesar, was imprisoned in 30. That year Sejanus was elected consul for 31 with Tiberius amid engineered demonstrations; a grant of proconsular power followed, and he hoped for tribunician power. In October, however, Tiberius, allegedly warned by his sister-in-law Antonia, sent a letter to the senate which ended by denouncing him (certainly of plotting against Germanicus’ youngest son, Gaius (1) ‘Caligula’ (the future emperor). Sejanus was arrested, the guard having been transferred to Macro, ‘tried’ in the senate, and executed; the punishment of Livilla and of adherents, real or alleged, followed; even his youngest children were killed. Tiberius acted quickly and in fear of the outcome. Sejanus has been suspected of planning a coup against him; more probably he intended a gradual accession to partnership, involving Livia Julia’s son Tiberius Julius Caesar Nero ‘Gemellus’.
John Percy Vyvian Dacre Balsdon; Barbara M. Levick
Subjects: Classical Studies.