The praetorian prefect (; ) was a high office in the
Roman Empire
The Roman Empire ruled the Mediterranean and much of Europe, Western Asia and North Africa. The Roman people, Romans conquered most of this during the Roman Republic, Republic, and it was ruled by emperors following Octavian's assumption of ...
. 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
Constantine I (27 February 27222 May 337), also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a Constantine the Great and Christianity, pivotal ro ...
, the office was much reduced in power and transformed into a purely civilian administrative post, while under his successors, territorially-defined
praetorian prefecture
The praetorian prefecture (; in Ancient Greek, Greek variously named ) was the largest administrative division of the Late Antiquity, late Roman Empire, above the mid-level Roman diocese, dioceses and the low-level Roman province, provinces. Praeto ...
s 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
The Ostrogothic Kingdom, officially the Kingdom of Italy (), was a barbarian kingdom established by the Germanic Ostrogoths that controlled Italian peninsula, Italy and neighbouring areas between 493 and 553. Led by Theodoric the Great, the Ost ...
) 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
The Byzantine Empire, also known as the Eastern Roman Empire, was the continuation of the Roman Empire centred on Constantinople during late antiquity and the Middle Ages. Having survived History of the Roman Empire, the events that caused the ...
by the 840s.
The term ''praefectus praetorio'' was often abbreviated in inscriptions as "PR PR" or "PPO".
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
The (; , though sometimes referred to as " knights" in English) constituted the second of the property/social-based classes of ancient Rome, ranking below the senatorial class. A member of the equestrian order was known as an ().
Descript ...
and held office at his pleasure. From the time of
Alexander Severus
Marcus Aurelius Severus Alexander (1 October 208 – March 235), also known as Alexander Severus, was Roman emperor from 222 until 235. He was the last emperor from the Severan dynasty. Alexander took power in 222, when he succeeded his slain co ...
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
Prefect (from the Latin ''praefectus'', substantive adjectival form of ''praeficere'': "put in front", meaning in charge) is a magisterial title of varying definition, but essentially refers to the leader of an administrative area.
A prefect' ...
, the ''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'état 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
Diocletian ( ; ; ; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia (Roman province), Dalmatia. As with other Illyri ...
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. By the time of Diocletian he had become a kind of grand-vizier as the emperor's vice-regent and 'prime minister.' Constantine removed active military command in 312. The prefect remained as chief quarter-master general responsible for the logistical supply of the army. The prefect was the chief financial officer whose office drew up the global imperial budget. His office drew up the state liturgical obligations laid on the richer inhabitants of the Empire. He ceased to be head of administration which had to be shared with the master of the offices attached to the palace. Constantine in 331 confirmed 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
Lucius Septimius Severus (; ; 11 April 145 – 4 February 211) was Roman emperor from 193 to 211. He was born in Leptis Magna (present-day Al-Khums, Libya) in the Roman province of Africa. As a young man he advanced through cursus honorum, the ...
. Hence a knowledge of law became a qualification for the post, which under
Marcus Aurelius
Marcus Aurelius Antoninus ( ; ; 26 April 121 – 17 March 180) was Roman emperor from 161 to 180 and a Stoicism, Stoic philosopher. He was a member of the Nerva–Antonine dynasty, the last of the rulers later known as the Five Good Emperors ...
and
Commodus
Commodus (; ; 31 August 161 – 31 December 192) was Roman emperor from 177 to 192, first serving as nominal co-emperor under his father Marcus Aurelius and then ruling alone from 180. Commodus's sole reign is commonly thought to mark the end o ...
, but especially from the time of Severus, was held by the first jurists of the age, (e.g.
Papinian,
Ulpian
Ulpian (; ; 223 or 228) was a Roman jurist born in Tyre in Roman Syria (modern Lebanon). He moved to Rome and rose to become considered one of the great legal authorities of his time. He was one of the five jurists upon whom decisions were to ...
,
Paulus) and, under
Justinianus,
John the Cappadocian
John the Cappadocian () (''Floruit, fl.'' 530s, living 548) was a praetorian prefect of the East (532–541) in the Byzantine Empire under Byzantine Emperor, Emperor Justinian I (r. 527–565). He was also a Patrikios, patrician and the ''Roman ...
, while the military qualification fell more and more into the background.
[
The ]tetrarchy
The Tetrarchy was the system instituted by Roman emperor Diocletian in 293 AD to govern the ancient Roman Empire by dividing it between two emperors, the ''augusti'', and their junior colleagues and designated successors, the ''caesares''.
I ...
reform of Diocletian
Diocletian ( ; ; ; 242/245 – 311/312), nicknamed Jovius, was Roman emperor from 284 until his abdication in 305. He was born Diocles to a family of low status in the Roman province of Dalmatia (Roman province), Dalmatia. As with other Illyri ...
() multiplied the office: there was a praetorian prefect as chief of staff (military and administrative)—rather than commander of the guard—for each of the two Augusti, but not for the two Caesars. Each praetorian prefect oversaw one of the four quarters created by Diocletian, which became regional praetorian prefecture
The praetorian prefecture (; in Ancient Greek, Greek variously named ) was the largest administrative division of the Late Antiquity, late Roman Empire, above the mid-level Roman diocese, dioceses and the low-level Roman province, provinces. Praeto ...
s for the young sons of Constantine ca 330 A.D. From 395 there were two imperial courts, at Rome
Rome (Italian language, Italian and , ) is the capital city and most populated (municipality) of Italy. It is also the administrative centre of the Lazio Regions of Italy, region and of the Metropolitan City of Rome. A special named with 2, ...
(later Ravenna
Ravenna ( ; , also ; ) is the capital city of the Province of Ravenna, in the Emilia-Romagna region of Northern Italy. It was the capital city of the Western Roman Empire during the 5th century until its Fall of Rome, collapse in 476, after which ...
) and Constantinople
Constantinople (#Names of Constantinople, see other names) was a historical city located on the Bosporus that served as the capital of the Roman Empire, Roman, Byzantine Empire, Byzantine, Latin Empire, Latin, and Ottoman Empire, Ottoman empire ...
, but the four prefectures remained as the highest level of administrative division, in charge of several diocese
In Ecclesiastical polity, church governance, a diocese or bishopric is the ecclesiastical district under the jurisdiction of a bishop.
History
In the later organization of the Roman Empire, the increasingly subdivided Roman province, prov ...
s (groups of Roman province
The Roman provinces (, pl. ) were the administrative regions of Ancient Rome outside Roman Italy that were controlled by the Romans under the Roman Republic and later the Roman Empire. Each province was ruled by a Roman appointed as Roman g ...
s), each of which was headed by a Vicarius.
Under Constantine I
Constantine I (27 February 27222 May 337), also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a Constantine the Great and Christianity, pivotal ro ...
, the institution of the magister militum
(Latin for "master of soldiers"; : ) was a top-level military command used in the late Roman Empire, dating from the reign of Constantine the Great. The term referred to the senior military officer (equivalent to a war theatre commander, the e ...
deprived the praetorian prefecture altogether of its military character but left it the highest civil office of the empire.[
]
Post-imperial era
With the fall of the western part of the Empire into the hands of warlords, these, in order to have support in their new domains, recognized the supremacy of the emperor of the eastern part, reuniting at least '' de iure'' the Empire under him, the prefectures were maintained as a way of delimiting the new viceroyalties:
* First Flavius Odoacer and later Flavius Theodoricus were granted the prefecture of Italy;
* Louis I was recognized as the prefect of Gaul (which served him as a pretext to seize the Visigoth
The Visigoths (; ) were a Germanic people united under the rule of a king and living within the Roman Empire during late antiquity. The Visigoths first appeared in the Balkans, as a Roman-allied barbarian military group united under the comman ...
s' territories in Gaul);
* the Visigoths were recognized for their dominion over the prefecture of Hispania;
* and the Vandal
The Vandals were a Germanic people who were first reported in the written records as inhabitants of what is now Poland, during the period of the Roman Empire. Much later, in the fifth century, a group of Vandals led by kings established Vandal ...
s theirs over Africa.
This recognition would be maintained until the rise of Justinian I
Justinian I (, ; 48214 November 565), also known as Justinian the Great, was Roman emperor from 527 to 565.
His reign was marked by the ambitious but only partly realized ''renovatio imperii'', or "restoration of the Empire". This ambition was ...
, who ended the Ostrogothic and Vandal domains, but continued to recognize the Franks (as they were both Catholics) and the Visigoths (due to the lack of strength to continue the '' Recuperatio Imperii'', but managing to establish a pro-Byzantine king, Athanagild
Athanagild ( 517 – December 567) was the Visigothic king of Hispania and Septimania. He had rebelled against his predecessor, Agila I, in 551. The armies of Agila and Athanagild met at Seville, where Agila met a second defeat. Following the dea ...
, and the conquest of Spania
Spania () was a Roman province, province of the Eastern Roman Empire from 552 until 624 in the south of the Iberian Peninsula and the Balearic Islands. It was established by the List of Byzantine emperors, Emperor Justinian I in an effort to res ...
).
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.[Dates from 2 BC to AD 260 based on Guy de la Bédoyère, ''Praetorian'' (New Haven: Yale Press, 2017), pp. 280-282] The list is presumed to be incomplete due to the 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
Lucius Aelius Sejanus ( – 18 October AD 31), commonly known as Sejanus (), 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 imperia ...
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)
Year of the Four Emperors (AD 68–69)
Flavian dynasty
The Flavian dynasty, lasting from 69 to 96 CE, was the second dynastic line of emperors to rule the Roman Empire following the Julio-Claudian dynasty, Julio-Claudians, encompassing the reigns of Vespasian and his two sons, Titus and Domitian. Th ...
(AD 69–96)
Five Good Emperors to
Didius Julianus
Marcus Didius Julianus (; 29 January 133 – 2 June 193) was Roman emperor from March to June 193, during the Year of the Five Emperors. Julianus had a promising political career, governing several provinces, including Dalmatia (Roman province) ...
(AD 96–193)
Severan dynasty
The Severan dynasty, sometimes called the Septimian dynasty, ruled the Roman Empire between 193 and 235.
It was founded by the emperor Septimius Severus () and Julia Domna, his wife, when Septimius emerged victorious from civil war of 193 - 197, ...
(AD 193–235)
Crisis of the Third Century
The Crisis of the Third Century, also known as the Military Anarchy or the Imperial Crisis, was a period in History of Rome, Roman history during which the Roman Empire nearly collapsed under the combined pressure of repeated Barbarian invasions ...
(AD 235–285)
Tetrarchy
The Tetrarchy was the system instituted by Roman emperor Diocletian in 293 AD to govern the ancient Roman Empire by dividing it between two emperors, the ''augusti'', and their junior colleagues and designated successors, the ''caesares''.
I ...
to Constantine I
Constantine I (27 February 27222 May 337), also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a Constantine the Great and Christianity, pivotal ro ...
(AD 285–324)
See also
For praetorian prefects after the reformation of the office by emperor Constantine I
Constantine I (27 February 27222 May 337), also known as Constantine the Great, was a Roman emperor from AD 306 to 337 and the first Roman emperor to convert to Christianity. He played a Constantine the Great and Christianity, pivotal ro ...
, see:
* Praetorian prefecture of Italy
*Praetorian prefecture of Gaul
The Praetorian Prefecture of Gaul () was one of four large praetorian prefecture, prefectures into which the Late Roman Empire was divided in the 4th century.
History
The prefecture was established after the death of Constantine I in 337, whe ...
*Praetorian prefecture of the East
The praetorian prefecture of the East, or of the Orient (, ) was one of four large praetorian prefectures into which the Later Roman Empire, Late Roman Empire was divided. As it comprised the larger part of the Eastern Roman Empire, and its seat w ...
*Praetorian prefecture of Illyricum
The praetorian prefecture of Illyricum (; , also termed simply the prefecture of Illyricum) was one of four praetorian prefectures into which the Later Roman Empire, Late Roman Empire was divided.
The administrative centre of the prefecture wa ...
A further prefecture was established by emperor Justinian I
Justinian I (, ; 48214 November 565), also known as Justinian the Great, was Roman emperor from 527 to 565.
His reign was marked by the ambitious but only partly realized ''renovatio imperii'', or "restoration of the Empire". This ambition was ...
in the 6th century:
* Praetorian prefecture of Africa
Notes
References
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{{DEFAULTSORT:Praetorian Prefect
Ancient Roman titles
Gubernatorial titles
Lists of office-holders in ancient Rome
Lists of ancient Roman equites
Military ranks of ancient Rome
Positions of authority
Praetorian Guard
1st-century BC establishments in the Roman Empire
4th-century disestablishments in the Roman Empire