Lucius Seius Strabo (46 BC16 AD) was a prefect of the Roman imperial bodyguard, known as the Praetorian Guard, during the rule of the emperors Augustus and Tiberius. The length of Strabo's tenure as Praetorian prefect is unknown, but he held the position together with various colleagues until 15, after which he was appointed to the governorship of Egypt. With this career Strabo distinguished himself by attaining the two highest offices open to men of the equestrian class in the Roman Empire. His son was Lucius Aelius Sejanus, who succeeded his father as Praetorian prefect in 15, and gained great influence under Emperor Tiberius before dramatically falling from power in 31. Family Lucius Seius Strabo was born around 46 BC in Volsinii, Etruria, to the family of Marcus Seius Strabo and Terentia. Although the Seii were Romans of the equestrian class, Strabo's father maintained relations with senatorial families through his marriage with Terentia. Her brother was Aulus Terentius Varro Murena, who shared the consulship with Augustus in 23 BC, and her sister, a more well known Terentia, was the wife of Augustus' political ally Maecenas. Strabo himself married into equally illustrious families. His first wife was Aelia, the daughter of Quintus Aelius Tubero, a marriage by which he allied himself with the more prestigious Aelian gens. By Aelia, he had one son, Lucius Seius Tubero, who became suffect consul in 18. After her death, he married Cosconia Lentuli Maligunensis Gallita, sister of Servius Cornelius Lentulus Maluginensis (suffect consul in 10), Publius Cornelius Lentulus Scipio (suffect consul in 2), and half sister of Quintus Junius Blaesus (suffect consul in 10). With Cosconia Strabo had one son, Lucius Seius, who was later adopted into the Aelian gens and became known as Lucius Aelius Seianus, or simply Sejanus. Career Under Augustus The equestrian class was one of the two upper social classes of the Roman Republic and the early Roman Empire. Officially, they were the second tier of the elite, behind the patrician or senatorial class. This made them relatively harmless and consequently, suitable for important offices of state such as Praetorian prefect or governor of Egypt; the former post which was in charge of the Emperor's personal bodyguard, the latter which controlled the grain supply of Rome. A senator who occupied such positions might develop ambitions of making himself emperor, a danger Augustus was well aware of. The Praetorian Guard was formally