Praetorian prefect
Prefect Tenure Emperor served
Afranius Hannibalianus 286/292 Diocletian
Asclepiades 303 ( at Antioch )
Pomponius Januarianus 285/286 Maxentius
Julius Asclepiodotus 290 - 296 Diocletian ; Constantius Chlorus
Constantius Chlorus ? ? - ? ? Diocletian
Manlius Rusticianus 306 - 310 Maxentius
Gaius Caeionius Rufius Volusianus 309 - 310 Maxentius
Ruricius Pompeianus ? ? - 312 Maxentius
Tatius Andronicus 310 Galerius
Pompeius Probus 310 - 314 Licinius
Petronius Annianus 315 - 317 Constantine I
Julius Julianus 315 - 324 Licinius
Junius Annius Bassus 318 - 331 Constantine I
List of known prefects of the Praetorian Guard -- Tetrarchy to Constantine I ( AD 285 – 324 )
The praetorian prefect (, ) was a high office in the Roman Empire. Originating as the commander of the Praetorian Guard, the office gradually acquired extensive legal and administrative functions, with its holders becoming the Emperor's chief aides. Under Constantine I, the office was much reduced in power and transformed into a purely civilian administrative post, while under his successors, territorially-defined praetorian prefectures emerged as the highest-level administrative division of the Empire. The prefects again functioned as the chief ministers of the state, with many laws addressed to them by name. In this role, praetorian prefects continued to be appointed by the Eastern Roman Empire (and the Ostrogothic Kingdom) until the reign of Heraclius in the 7th century AD, when wide-ranging reforms reduced their power and converted them to mere overseers of provincial administration. The last traces of the prefecture disappeared in the Byzantine Empire by the 840s. The term praefectus praetorio was often abbreviated in inscriptions as 'PR PR' or 'PPO'.