Lucius Aelius Sejanus (c. 20 BC – 18 October AD 31), commonly known as Sejanus (), was a Roman soldier, friend, and confidant of the Roman Emperor Tiberius. Of the Equites class by birth, Sejanus rose to power as prefect of the Praetorian Guard, the imperial bodyguard, of which he was commander from AD 14 until his execution for treason in AD 31. https://en.wikipedia.org/wiki/Sejanus