Praetorian Guard
She was born into the family of the Aelii Tuberones, and thus apparently descended from the consul of 11 BC, Q. Aelius Tubero. Her father may have died when she was very young, as she was raised by a relative—Praetorian Guard Prefect Lucius Seius Strabo, the biological father of her adoptive brother Lucius Aelius Sejanus, commander of the Praetorian Guard under the Emperor Tiberius.