Lucius Aelius Seianus (20 BC – October 18, AD 31), commonly known as
Sejanus (
English pronunciation: ), was an ambitious soldier, friend and confidant of the
Roman Emperor Tiberius. An
equestrian by birth, Sejanus rose to power as
prefect of the Roman imperial
bodyguard, known as the
Praetorian Guard, of which he was commander from AD 14 until his death in AD 31.