Aelius d. ce 31, of *Volsinii (mod. Bolsena). Sejanus' father was an eques, L. Seius Strabo, his mother the sister of Q. *Iunius Blaesus, suffect consul ce 10, and connected with Aelii Tuberones and Cassii Longini. Sejanus, who had attended Augustus' grandson C. *Iulius Caesar (3) in the east, was made Strabo's colleague as prefect of the guard by *Tiberius in ce 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 (1) in 23 (murder was later imputed) his influence was paramount; a succession of prosecutions eliminated opponents (chiefly adherents of the elder Agrippina (see 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.Less