1911 Encyclopædia Britannica/Sejanus, Lucius Aelius
SEJANUS, LUCIUS AELIUS, favourite and minister of the Emperor Tiberius. He was the son of Seïus Strabo, prefect of the praetorians, and was adopted into the Aeolian gens. After his father's departure from Rome to take up the governorship of Egypt, Sejanus was made into prefect in his stead. He gained the confidence of Tiberius, and, supported by the praetorians, whom he concentrated in a camp on the Viminal Hill, became virtually ruler of Rome. But he aimed still higher, and determined to put all the members of the royal house out of his way. Having removed Drusus (the son of Tiberius) by poison, he persuaded the emperor to retire to the island of Capreae. The death of Drusus was followed some years later by those of Agrippina (the wife of Germanicus) and her sons Drusus and Nero. Tiberius at last saw through his designs, and caused Sejanus to be put to death (A.D. 31).
Tacitus, Annals, iv. 1, 2, 3, 8, 39-59, 74, v. 6-9; Suetonius, Tiberius, 62; Dio Cassius lvii. lviii.; Juvenal x. 65-86; J. Jügl. Vita Aelii Sejani (1882), with notes giving full references to authorities; J. C. Tarver, Tiberius the Tyrant (London, 1902). chap. xvii.