Of Volsinïï, d. ad 31. Sejanus' father was an equestrian, Seius Strabo. Sejanus, who had attended Augustus' grandson Gaius Iulius Caesar 2 in the east, was made Strabo's colleague as praetorian prefect 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 Iulius Caesar in 23 (murder was later imputed) his influence was paramount; a succession of prosecutions eliminated opponents (chiefly adherents of Vipsania Agrippina 2). Tiberius allegedly refused to allow a marriage with Drusus' widow Livia Iulia (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 Iulius Caesar were deported; her second, Drusus Iulius Caesar, was imprisoned in 30. That year Sejanus was elected consul for 31 with Tiberius amid engineered demonstrations; proconsular imperium followed, and he hoped for tribunician power. In October, however, Tiberius, allegedly warned by his sister‐in‐law Antonia 2, sent a letter to the senate which ended by denouncing him (certainly for plotting against Germanicus' youngest son, Gaius 1 ‘Caligula’ ). Sejanus was arrested, the guard having been transferred to Sutorius Macro, tried in the senate, and executed; the punishment of Livia lulia 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 Iulia's son Iulius Caesar Nero ‘Gemellus’.
Subjects: Classical Studies.