Sejanus
confidant of the Roman Emperor Tiberius and prefect of the Roman imperial Praetorian Guard (20 BC - AD 31)
Lucius Aelius Sejanus ( ; c. 20 BC – 18 October AD 31) was a Roman soldier 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.
While the Praetorian Guard was formally established under Emperor Augustus, Sejanus introduced a number of reforms which saw the unit evolve beyond a mere bodyguard into a powerful and influential branch of the government involved in public security, civil administration and ultimately political intercession; these changes had a lasting impact on the course of the Principate.
During the 20s, Sejanus gradually accumulated power by consolidating his influence over Tiberius and eliminating potential political opponents, including the emperor's son Drusus Julius Caesar. When Tiberius withdrew to Capri in AD 26, Sejanus was left in control of the administration of the empire. For a time the most influential and feared citizen of Rome, Sejanus suddenly fell from power in AD 31, the year his career culminated with the consulship. Amidst suspicions of conspiracy against Tiberius, Sejanus was arrested and executed, along with his followers.
Family
Sejanus was born around 20 BC at Volsinii, Etruria, into the Seia gens. His father was Lucius Seius Strabo. The Seii were Romans of the Equites class (or knights), the second-highest social class of the Roman Republic and the early Roman Empire.
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Named sources, stable identifiers and responsible institutions provide the strongest route from overview to verifiable evidence. The source revision retrieved here is dated Aug 23, 2026. The linked authority identifier is Q120015. VIAF identifies the subject as 13551480. The Library of Congress control number is n50005907. 3 of 3 selected statements include explicit references; 0 carry qualifiers and 0 use preferred rank.
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This entry incorporates text from “Sejanus” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.