Praetorian prefect (Latin: praefectus praetorio, Greek: ἔπαρχος/ὕπαρχος τῶν πραιτωρίων) was the title of 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 until the reign of Heraclius, when wide-ranging reforms reduced its power and converted it to a mere overseer of provincial administration. The last traces of the prefect disappeared in the Byzantine Empire in the 840s.

The term praefectus praetorio was often abbreviated in inscriptions as 'PR PR'.[1]

History

Commander of the Praetorian Guard

Under the empire the praetorians or imperial guards were commanded by one, two, or even three praefects (praefecti praetorio), who were chosen by the emperor from among the equites and held office at his pleasure. From the time of Alexander Severus the post was open to senators also, and if an equestrian was appointed he was at the same time raised to the senate. Down to the time of Constantine, who deprived the office of its military character, the prefecture of the guards was regularly held by tried soldiers, often by men who had fought their way up from the ranks. In course of time the command seems to have been enlarged so as to include all the troops in Italy except the corps commanded by the city praefect (cohortes urbanae).

The special position of the praetorians made them a power in their own right in the Roman state, and their prefect, praefectus praetorio, soon became one of the more powerful men in this society. The emperors tried to flatter and control the praetorians, but they staged many coups d'etat and contributed to a rapid rate of turnover in the imperial succession. The praetorians thus came to destabilize the Roman state, contrary to their purpose. The praetorian prefect became a major administrative figure in the later empire, when the post combined in one individual the duties of an imperial chief of staff with direct command over the guard also. Diocletian greatly reduced the power of these prefects as part of his sweeping reform of the empire's administrative and military structures.

Transformation to administrator

In addition to his military functions, the praetorian prefect came to acquire jurisdiction over criminal affairs, which he exercised not as the delegate but as the representative of the emperor. It was decreed by Constantine 331 that from the sentence of the praetorian praefect there should be no appeal. A similar jurisdiction in civil cases was acquired by him not later than the time of Septimius Severus. Hence a knowledge of law became a qualification for the post, which under Marcus Aurelius and Commodus, but especially from the time of Severus, was held by the first jurists of the age, (e.g. Papinian, Ulpian, Paullus) and John the Cappadocian, while the military qualification fell more and more into the background.

The tetrarchy reform of Diocletian (c. 296) multiplied the office, as there was now one pretorian prefect as chief of staff (military and administrative)—rather than commander of the guard—for each of the two Augusti and two Caesares. Each one of the pretorian perfects oversaw one of the four quarters created by Diocletian, which would become praetorian prefectures under Constantine. Their masters were soon reduced to two imperial courts, at Rome (later Ravenna) and Constantinople, but the four prefectures remained as the highest level of administrative division, in charge of several so-called dioceses (groups of Roman provinces), each of which was headed by a Vicarius.

Under Constantine I, the institution of the magister militum deprived the praetorian prefecture altogether of its military character but left it the highest civil office of the empire.

Germanic era

The office was among the many maintained after the Western Roman Empire had succumbed to the Germanic invasion in Italy, notably at the royal court of the Ostrogothic king Theoderic the Great, who as a nominal subject of Constantinople retained the Roman-era administration intact.

List of known prefects of the Praetorian Guard

The following is a list of all known prefects of the Praetorian Guard, from the establishment of the post in 2 BC by Augustus until the abolishment of the Guard in 314. The list is presumed to be incomplete due to lack of sources documenting the exact number of persons who held the post, what their names were and what the length of their tenure was. Likewise, the Praetorians were sometimes commanded by a single prefect, as was the case with for example Sejanus or Burrus, but more often, the emperor appointed two commanders, who shared joint leadership. Overlapping terms on the list indicate dual command.

Julio-Claudian dynasty (2 BC – AD 68)

Prefect Tenure Emperor served
Publius Salvius Aper 2 BC – ?? Augustus
Quintus Ostorius Scapula 2 BC – ?? Augustus
Publius Varius Ligur[2]  ?? – ?? Augustus
Lucius Seius Strabo  ?? – 15 Augustus, Tiberius
Lucius Aelius Sejanus 14 – 31 Tiberius
Quintus Naevius Sutorius Macro 31 – 38 Tiberius, Caligula
Marcus Arrecinus Clemens 38 – 41 Caligula
Lucius Arruntius Stella[3] 38 – 41 Caligula
Rufrius Pollio 41 – 43 Claudius
Catonius Justus 41 – 43 Claudius
Rufrius Crispinus 43 – 50 Claudius
Lucius Lusius Geta 47 – 50 Claudius
Sextus Afranius Burrus 50 – 62 Claudius, Nero
Lucius Faenius Rufus 62 – 65 Nero
Gaius Ofonius Tigellinus 62 – 68 Nero
Gaius Nymphidius Sabinus 65 – 68 Nero

Year of the Four Emperors (AD 68 – 69)

Prefect Tenure Emperor served
Cornelius Laco 68 – 69 Galba
Plotius Firmus 69 – 69 Otho
Licinius Proculus 69 – 69 Otho
Publius Sabinus 69 – 69 Vitellius
Alfenius Varus 69 – 69 Vitellius
Junius Priscus 69 – 69 Vitellius

Flavian dynasty (AD 69 – 96)

Prefect Tenure Emperor served
Arrius Varus 69 – 70 Vespasian
Marcus Arrecinus Clemens[4] 70 – 71 Vespasian
Tiberius Julius Alexander[5] 69 – ?? Vespasian
Titus Flavius Vespasianus[6] 71 – 79 Vespasian
Lucius Julius Ursus[7] 81 – 83 Domitian
Cornelius Fuscus 81 – 86 Domitian
Lucius Laberius Maximus[7] 83 – 84 Domitian
Casperius Aelianus 84 – 94 Domitian
Titus Flavius Norbanus 94 – 96 Domitian
Titus Petronius Secundus 94 – 96 Domitian

Five Good Emperors to Didius Julianus (AD 96 – 193)

Prefect Tenure Emperor served
Casperius Aelianus 96 – 98 Nerva
Sextus Attius Suburanus 98 – 101 Trajan
Tiberius Claudius Livianus 101 – ?? Trajan
Publius Acilius Attianus[8]  ?? – 119 Trajan, Hadrian
Servius Sulpicius Similis 112 – 119 Trajan, Hadrian
Gaius Septicius Clarus 119 – 121 Hadrian
Quintus Marcius Turbo 119 – ?? Hadrian
Marcus Petronius Mamertinus 139 – 143 Hadrian, Antoninus Pius
Marcus Gavius Maximus 136 – 156 Hadrian, Antoninus Pius
Gaius Tattius Maximus 156 – 159 Antoninus Pius
Fabius Cornelius Repentinus 159 – ?? Antoninus Pius
Furius Victorinus 160 – 168 Antoninus Pius, Marcus Aurelius
Macrinius Vindex  ?? – ?? Marcus Aurelius
Marcus Bassaeus Rufus 168 – 177 Marcus Aurelius
Publius Tarrutenius Paternus by 179 – 182? Marcus Aurelius, Commodus
Sextus Tigidius Perennis 180 – 185 Commodus
Niger 185 – 185 Commodus
Marcius Quartus 185 – 185 Commodus
Titus Longaeus Rufus 185 – by 187 Commodus
Publius Atilius Aebutianus c. 185 – c. 187 Commodus
Marcus Aurelius Cleander c. 187 – 189? Commodus
Lucius Julius Vehilius Gratus Julianus 188 – c. 189 Commodus
Regillus c. 189 – c. 189 Commodus
Motilenus c. 190 – c. 190 Commodus, Pertinax, Didius Julianus
Quintus Aemilius Laetus 192 – 193 Commodus, Pertinax, Didius Julianus
Titus Flavius Genialis 193 – 193 Didius Julianus
Tullius Crispinus 193 – 193 Didius Julianus

Severan dynasty (AD 193 – 235)

Prefect Tenure Emperor served
Flavius Juvenalis 193 – by 200 Didius Julianus, Septimius Severus
Decimus Veturius Macrinus 193 – by 200 Didius Julianus, Septimius Severus
Gaius Fulvius Plautianus 197? – 205 Septimius Severus
Quintus Aemilius Saturninus 200 – 200 Septimius Severus
Marcus Aurelius Julianus c. 200/205 Septimius Severus, Caracalla
Marcus Flavius Drusianus c. 204/204 Septimius Severus, Caracalla
Aemilius Papinianus 205 – 211 Septimius Severus, Caracalla
Quintus Maecius Laetus 205 – 215? Septimius Severus, Caracalla
Valerius Patruinus 211? – 212 Caracalla
Gnaeus Marcius Rustius Rufinus c. 212 – c. 217 Caracalla
Marcus Oclatinius Adventus 215? – 217 Caracalla
Marcus Opellius Macrinus[9] 212? – 217 Caracalla
Ulpius Julianus 217? – 218 Macrinus
Julianus Nestor 217? – 218 Macrinus
Julius Basilianus 218 – 218 Elagabalus
Publius Valerius Comazon Eutychianus 218 – 222 Elagabalus
Antiochianus 221 – 221 Elagabalus
Flavianus 222 – ?? Alexander Severus
Geminius Chrestus 222 – ?? Alexander Severus
Gnaeus Domitius Annius Ulpianus 222 – ?? Alexander Severus
Lucius Domitius Honoratus 223/226 – ?? Alexander Severus
Marcus Aedinius Julianus 223? – by 238 Alexander Severus
Marcus Attius Cornelianus c. 230 – c. 230 Alexander Severus

Crisis of the Third Century (AD 235 – 285)

Prefect Tenure Emperor served
Vitalianus  ?? – 238 Maximinus Thrax
Annullinus  ?? – 238 Maximinus Thrax
Pinarius Valens 238 – 238 Pupienus; Balbinus
Domitius by. 240 – ?? Gordian III
Gaius Furius Sabinius Aquila Timesitheus 241 – 243 Gordian III
Gaius Julius Priscus 242 – after 246 Gordian III; Philip the Arab
Marcus Julius Philippus 243 – 244 Gordian III
Maecius Gordianus 244 – 244 Gordian III
Quintus Herennius Potens 249? – 251 Decius?
Successianus c. 257 – 260 Valerian
Silvanus  ?? – c. 260 Gallienus
Callistus Ballista 260 – 261 Macrianus, Quietus
Lucius Petronius Taurus Volusianus c. 260 – c. 267 Gallienus
Marcus Aurelius Heraclianus by 268 – ?? Gallienus
Julius Placidianus c. 270 – c. 275 Aurelian
Marcus Annius Florianus 275? – 276 Tacitus
Marcus Aurelius Carus  ?? – 282 Probus
Lucius Flavius Aper 282? – 284 Numerian
Marcus Aurelius Sabinus Julianus c. 283? – c. 284 Carinus
Titus Claudius Marcus Aurelius Aristobulus 284 – 285 Carinus; Diocletian

Tetrarchy to Constantine I (AD 285 – 324)

Prefect Tenure Emperor served
Afranius Hannibalianus 285/297 Diocletian
Julius Asclepiodotus 285/297 Diocletian; Constantius Chlorus
Constantius Chlorus  ?? – ?? Diocletian
Rufius Volusianus  ?? – ?? Maxentius
Publius Cornelius Anullinus  ?? – ?? Maxentius
Ruricius Pompeianus  ?? – 312 Maxentius
Julius Julianus 315 – 324 Licinius
Junius Annius Bassus 318 – 331 Constantine I

For praetorian prefects after the reformation of the office by emperor Constantine I, see Praetorian prefecture of Italy, Praetorian prefecture of Gaul, Praetorian prefecture of Illyricum, Praetorian prefecture of Africa, and Praetorian prefecture of the East.