Praefectus Praetorio

• The Praefectus Praetorio was the Commander of the Praetorian Guard.
• This was the Roman Emperor’s personal Regiment based in the Castra Praetoria in Rome.

Description

• The Praefectus Praetorio was an Equestrian, and not from the Senatorial Class.
• He was the Emperor’s right hand man, and was the second most powerful man in the Roman Empire after the Emperor.
• During the Crisis of the Third Century the Praetorian Prefects often decided the succession of one Emperor after another, sometimes by auction.
• The Emperors appointed between one to three Prefects of the Praetorian Guard at the same time, as they did not trust one man to wield so much power.

Command Structure of the Praetorian Guard

• Praetorian Prefect:
  • Commander of the Praetorian Guard in charge of the 9 Cohorts and the Cavalry wing.
• Praetorian Tribune:
  • He commanded each Cohort along with two subordinates – all three from the Equestrian class.
• Praetorian Centurion:
  • He had to be a Roman Citizen, recruited from Italia, mainly Etruria, Umbria and Latium.
• Praetorian Legionary:
  • He had to be a Roman Citizen, recruited from Italia, mainly Etruria, Umbria and Latium.
• The Praetorian Cohorts:
  • Nine were formed initially: originally of 500 men, then increased to 1,000 men each. This created a force in Italy of 9,000 men – approximately 2 Legions.
• The Imperial Horse Guard had its own command structure.

Prefects of the Praetorian Guard who became the Roman Emperor

• Macrinus (217-218 CE)
• Philip the Arab (244-249 CE)
• Florianus (276 CE)

Famous Prefects of the Praetorian Guard

• Sejanus (13-31 CE)
  • under Tiberius and who was executed by him for Treason.
• Macro (31-38 CE)
  • under Tiberius and Caligula
• Tigellinus (25-68 CE)
  • under Nero
• Titus (Before 78 CE)
  • under his father Vespasian. Titus succeeded his father as Roman Emperor between 79-81 CE.
• Quintus Marcius Turbo (125-134 CE)
  • appointed by Hadrian, who trusted him to control Rome, whilst Hadrian was away for years travelling the Empire. Previously, Turbo had been Prefect of the Classis Misenensis under Trajan.
• Marcus Petronius Mamertinus (139-143 CE)
  • Appointed by Antoninus Pius after Mamertinus had served as Prefect of Egypt under Hadrian between 133-137 CE.
• Macrinus (212 CE)
  • before he himself became the Emperor.
• Marcus Oclatinus Adventus (c.215-217 CE)
  • He first became Head of the Frumentarii, then Prefect of the Praetorian Guard, and was finally promoted to become a Senator by Macrinus in 217 CE.
• Timesitheus: (241-243 CE)
  • He was Gordian III‘s father in law and Military Commander in the war against Parthia. Gordian III was only 13 when he was made Emperor. However, Timesitheus never took advantage of his position to usurp the Throne.
• Philip the Arab (244 – September 249 CE)
  • was made Praefectus by Gordian III, after Timesitheus died in Battle against the Parthians. When Gordian III died shortly afterwards, Philip the Arab was proclaimed Emperor.
• Successianus (c.252-260 CE)
  • Promoted by Valerian (although never confirmed by the historian Zosimus), after saving the city of Prityus, a port city in Colchis, from a seaborne attack by the Borani, a Scythian Tribe.
  • Successianus was invited to join Valerian in Antioch, Syria and his authority would have been in the Eastern Empire. Probably taken prisoner with Valerian after the Battle of Edessa in 260 CE.
• Silvanus (260 CE)
  • was Prefect under Gallienus. He was executed with Gallienus‘ son, Solinus, by Postumus.
• Under Gallienus (253-268 CE)
  • Aurelius Heraclianus and Claudius II Gothicus conspired to have Gallienus assassinated during the siege of Mediolanum.
• Victorinus
  • briefly Emperor of the Gallic Empire (268-270 CE), he probably served as Praetorian Prefect under Postumus. Postumus was assassinated by Marcus Aurelius Marius, who was then executed by Victorinus.
• Florianus (276 CE)
  • Prefect under Marcus Claudius Tacitus and was his half brother.

Castra Praetorio, Rome