The term TETRARCHY (from the Greek : τετραρχία, tetrarchia,
"leadership of four ") describes any form of government where power
is divided among four individuals, but in modern usage usually refers
to the system instituted by
Diocletian in 293, marking
the end of the
Crisis of the Third Century and the recovery of the
Roman Empire . This tetrarchy lasted until c. 313, when internecine
conflict eliminated most of the claimants to power, leaving
Constantine in control of the western half of the empire, and Licinius
in control of the eastern half.
* 1 Terminology
* 2 Creation
* 3 Regions and capitals
* 4 Public image
* 5 Military successes
* 6 Demise
* 7 Timeline
* 7.1 286–293
* 7.2 293–305
* 7.3 305–306
* 7.4 306–307
* 7.5 307–313
* 7.6 313–324
* 7.7 324
* 8 Others
* 8.1 1.
Tetrarchy until 1 May 305
* 8.2 2.
Tetrarchy until July 306
* 8.3 3.
Tetrarchy until 16 May 307
* 8.4 4.
Tetrarchy from 18 November 308 to the beginning of May 311
* 8.5 5.
Tetrarchy from May 311
* 8.6 (6.)
Tetrarchy after 8 October 316 to the end of 316
* 8.7 (7.)
Tetrarchy from 1 March 317 to 18 September 324
* 9 Legacy
* 10 Other examples
* 11 See also
* 12 Notes
* 13 Citations
* 14 References
* 15 External links
Although the term "tetrarch" was current in antiquity, it was never
used of the imperial college under Diocletian. Instead, the term was
used to describe independent portions of a kingdom that were ruled
under separate leaders. The tetrarchy of Judaea , established after
the death of
Herod the Great
Herod the Great , is the most famous example of the
antique tetrarchy. The term was understood in the
Latin world as well,
Pliny the Elder
Pliny the Elder glossed it as follows: "each is the equivalent
of a kingdom, and also part of one" (regnorum instar singulae et in
As used by the ancients, the term describes not only different
governments, but also a different system of government from the
Diocletianic arrangements. The Judaean tetrarchy was a set of four
independent and distinct states, where each tetrarch ruled a quarter
of a kingdom as they saw fit; the Diocletianic tetrarchy was a college
led by a single supreme leader. When later authors described the
period, this is what they emphasized: Ammianus had Constantius II
admonish Julian for disobedience by appealing to the example in
submission set by Diocletian's lesser colleagues; Julian himself
compared the Diocletianic tetrarchs to a chorus surrounding a leader,
speaking in unison under his command. Only
Lactantius , a contemporary
Diocletian and a deep ideological opponent of the Diocletianic
state, referred to the tetrarchs as a simple multiplicity of rulers.
Much modern scholarship was written without the term. Although Edward
Gibbon pioneered the description of the Diocletianic government as a
"New Empire", he never used the term "tetrarchy"; neither did Theodor
Mommsen . It did not appear in the literature until used in 1887 by
schoolmaster Hermann Schiller in a two-volume handbook on the Roman
Empire (Geschichte der Römischen Kaiserzeit), to wit: "die
diokletianische Tetrarchie". Even so, the term did not catch on in the
Otto Seeck used it in 1897.
The first phase, sometimes referred to as the
Diarchy ("rule of
two"), involved the designation of the general
co-emperor—firstly as Caesar (junior emperor) in 285, followed by
his promotion to Augustus in 286.
Diocletian took care of matters in
the eastern regions of the empire while
Maximian similarly took charge
of the western regions. In 293,
Diocletian thought that more focus was
needed on both civic and military problems, so with Maximian's
consent, he expanded the imperial college by appointing two Caesars
(one responsible to each Augustus)—
Galerius and Constantius Chlorus
In 305, the senior emperors jointly abdicated and retired, allowing
Galerius to be elevated in rank to Augustus. They in
turn appointed two new Caesars — Severus II in the west under
Constantius, and Maximinus in the east under
Galerius — thereby
creating the second Tetrarchy.
REGIONS AND CAPITALS
Map of the
Roman Empire under the Tetrarchy, showing the
dioceses and the four tetrarchs' zones of influence.
The four tetrarchs based themselves not at
Rome but in other cities
closer to the frontiers, mainly intended as headquarters for the
defence of the empire against bordering rivals (notably Sassanian
Persia ) and barbarians (mainly Germanic, and an unending sequence of
nomadic or displaced tribes from the eastern steppes) at the Rhine and
Danube. These centres are known as the tetrarchic capitals. Although
Rome ceased to be an operational capital,
Rome continued to be nominal
capital of the entire Roman Empire, not reduced to the status of a
province but under its own, unique
Prefect of the City (praefectus
urbis , later copied in Constantinople).
The four tetrarchic capitals were:
Nicomedia in northwestern
Asia Minor (modern
Izmit in Turkey), a
base for defence against invasion from the Balkans and Persia's
Sassanids was the capital of Diocletian, the eastern (and most senior)
Augustus; in the final reorganisation by Constantine the Great, in
318, the equivalent of his domain, facing the most redoubtable foreign
Sassanid Persia , became the pretorian prefecture Oriens, 'the
East', the core of later Byzantium.
Sremska Mitrovica in the
Vojvodina region of
Serbia , and near
Belgrade , on the
Danube border) was the
capital of Galerius, the eastern Caesar; this was to become the
Danube prefecture Illyricum.
Milan , near the Alps) was the capital of
Maximian, the western Augustus; his domain became "Italia et Africa",
with only a short exterior border.
Augusta Treverorum (modern
Trier , in Germany) was the capital of
Constantius Chlorus, the western Caesar, near the strategic Rhine
border; it had been the capital of Gallic emperor
Tetricus I . This
quarter became the prefecture Galliae.
Aquileia , a port on the Adriatic coast, and
in northern England near the Celtic tribes of modern Scotland and
Ireland), were also significant centres for
Maximian and Constantius
In terms of regional jurisdiction there was no precise division
between the four tetrarchs, and this period did not see the Roman
state actually split up into four distinct sub-empires. Each emperor
had his zone of influence within the Roman Empire, but little more,
mainly high command in a 'war theater'. Each tetrarch was himself
often in the field, while delegating most of the administration to the
hierarchic bureaucracy headed by his respective Pretorian
each supervising several
Vicarii , the governors-general in charge of
another, lasting new administrative level, the civil diocese . For a
listing of the provinces, now known as eparchy , within each quarter
(known as a praetorian prefecture), see
Roman province .
In the West, the Augustus
Maximian controlled the provinces west of
the Adriatic Sea and the Syrtis, and within that region his Caesar,
Gaul and Britain. In the East, the
arrangements between the Augustus
Diocletian and his Caesar, Galerius,
were much more flexible.
However, it appears that some contemporary and later writers, such as
the Christian author
Lactantius , and
Sextus Aurelius Victor (who
wrote about fifty years later and from uncertain sources),
misunderstood the tetrarchic system in this respect, believing it to
have involved a stricter division of territories between the four
Portrait of the Four Tetrarchs , a porphyry sculpture looted
from a Byzantine palace in 1204, now standing at the southwest corner
of St Mark\'s Basilica ,
Although power was shared in the tetrarchic system, the public image
of the four emperors in the imperial college was carefully managed to
give the appearance of a united empire (patrimonium indivisum). This
was especially important after the numerous civil wars of the 3rd
The tetrarchs appeared identical in all official portraits. Coinage
dating from the tetrarchic period depicts every emperor with identical
features—only the inscriptions on the coins indicate which one of
the four emperors is being shown. The Byzantine sculpture Portrait of
the Four Tetrarchs shows the tetrarchs again with identical features
and wearing the same military costume.
One of the greatest problems facing emperors in the Third Century
Crisis was that they were only ever able to personally command troops
on one front at any one time. While
Aurelian and Probus were prepared
to accompany their armies thousands of miles between war regions, this
was not an ideal solution. Furthermore, it was risky for an emperor to
delegate power in his absence to a subordinate general, who might win
a victory and then be proclaimed as a rival emperor himself by his
troops (which often happened). All members of the imperial college, on
the other hand, were of essentially equal rank, despite two being
senior emperors and two being junior; their functions and authorities
were also equal.
Tetrarchy a number of important military victories were
secured. Both the Dyarchic and the tetrarchic system ensured that an
emperor was nearby to every crisis area to personally direct and
remain in control of campaigns simultaneously on more than just one
front. After suffering a defeat by the Persians in 296, Galerius
Narseh in 298—reversing a series of Roman defeats throughout
the century—capturing members of the imperial household and a
substantial amount of booty and gaining a highly favourable peace
treaty, which secured peace between the two powers for a generation.
Similarly, Constantius defeated the British usurper
Maximian pacified the Gauls, and
Diocletian crushed the revolt of
Constantine at the battle of the Milvian Bridge , fresco by
Raphael , Vatican Rooms. Main article:
Civil wars of the Tetrarchy
When in 305 the 20-year term of
Maximian ended, both
abdicated. Their Caesares,
Galerius and Constantius Chlorus, were both
raised to the rank of Augustus, and two new Caesares were appointed:
Maximinus (Caesar to Galerius) and
Flavius Valerius Severus (Caesar to
Constantius). These four formed the second tetrarchy.
However, the system broke down very quickly thereafter. When
Constantius died in 306,
Galerius promoted Severus to Augustus while
Constantine , Constantius' son, was proclaimed Augustus by his
father's troops. At the same time,
Maxentius , the son of Maximian,
who also resented being left out of the new arrangements, defeated
Severus before forcing him to abdicate and then arranging his murder
Maximian both then declared themselves Augusti.
By 308 there were therefore no fewer than four claimants to the rank
of Augustus (Galerius, Constantine,
Maximian and Maxentius), and only
one to that of Caesar (Maximinus).
In 308 Galerius, together with the retired emperor
Diocletian and the
supposedly retired Maximian, called an imperial "conference" at
Carnuntum on the River Danube. The council agreed that
become Augustus in the West, with Constantine as his Caesar. In the
Galerius remained Augustus and Maximinus remained his Caesar.
Maximian was to retire, and
Maxentius was declared an usurper. This
agreement proved disastrous: by 308
Maxentius had become de facto
ruler of Italy and
Africa even without any imperial rank, and neither
Constantine nor Maximinus—who had both been Caesares since 306 and
305 respectively—were prepared to tolerate the promotion of the
Licinius as their superior.
After an abortive attempt to placate both Constantine and Maximinus
with the meaningless title filius Augusti ("son of the Augustus",
essentially an alternative title for Caesar), they both had to be
recognised as Augusti in 309. However, four full Augusti all at odds
with each other did not bode well for the tetrarchic system.
Between 309 and 313 most of the claimants to the imperial office died
or were killed in various civil wars. Constantine forced Maximian's
suicide in 310.
Galerius died naturally in 311.
Maxentius was defeated
by Constantine at the
Battle of the Milvian Bridge
Battle of the Milvian Bridge in 312 and
subsequently killed. Maximinus committed suicide at Tarsus in 313
after being defeated in battle by Licinius.
By 313, therefore, there remained only two emperors: Constantine in
the West and
Licinius in the East. The tetrarchic system was at an
end, although it took until 324 for Constantine to finally defeat
Licinius, reunite the two halves of the
Roman Empire and declare
himself sole Augustus.
This list (which may have dates, numbers, etc.) MAY BE BETTER IN A
SORTABLE TABLE FORMAT. Please help improve this list or discuss it on
the talk page . (November 2016)
A chart of the diarchy of 286-293 and subsequent tetrarchy of
293-305. Augusti Oriens
Diocletian (286–293) Occidens Maximian
Diocletian (286–305) Italia et
(286–305) Caesars Illyricum
Galerius (293–305) Gallia et Hispaniae
Constantius Chlorus (293–305) Usurpers Leaders of the
Gaul Amandus and Aelianus (285–286)
Africa Zeugitana Sabinus
Julianus (c. 285–293) Britannia
Carausius (286–293) Britannia
Domitius Domitianus (296–297) Aegyptus
Aurelius Achilleus (297–298)
A chart of the tetrarchy from 305 to 306, after the retirement
Diocletian and his colleague
Maximian , and the accession of
Galerius . Augusti Illyricum
Gallia, Hispaniae et Britannia
Constantius Chlorus (305–306) Caesars
Maximinus Daia (305–306) Italia et
Africa Flavius Valerius
A chart of the tetrarchy from 306 to 307. After the usurper
Maxentius declared himself Caesar, Augustus Severus marched on Rome
but was defeated when his troops deferred to
Maxentius . Severus was
later executed in the same year, 307. Maxentius, and his father and
former Augustus, Maximianus (
Maximian ), declared themselves Augusti
later that year. Augusti Illyricum
Galerius (306–307) Italia et
Flavius Valerius Severus (306–307) Caesars Oriens Maximinus
Daia (306–307) Gallia, Hispaniae et Britannia Constantine I
Maximianus joined the secessionist regime of his son, Maxentius
, in Italy. Constantine joined the secessionist alliance by marrying
Fausta , and by supporting
Maxentius in Italy.
However, Constantine remained neutral with
Galerius , but he still
took the title of Augustus in the secessionist regime. Augusti
Galerius (307–311) Gallia, Hispaniae et Britannia
Constantine I (307–…) Thracia et Pontus to Taurus Licinius
Maxentius (307–312) Oriens from Taurus to
Maximinus Daia (310–313) Italia
Caesars Oriens from Taurus to
Maximinus Daia (307–310)
Domitius Alexander (308–311)
Licinius (313–324) Occidens Constantine I
Sextus Martinianus (324) Caesars Italia
Bassianus (313–314) Illyricum
Valerius Valens (314–316) Oriens
Licinius the Younger (317–324) Occidens
1. TETRARCHY UNTIL 1 MAY 305
2. TETRARCHY UNTIL JULY 306
After the retirement of the two Augusti succeed the both previous
Caesares and appoint two new Caesares.
Maximinus Daia is the nephew of
3. TETRARCHY UNTIL 16 MAY 307
After the death of Constantius his legions proclamate his son
Constantin to be the new Augustus, but
Galerius elevates Severus to be
the new junior Augustus and compensates Constantin with the grade of
4. TETRARCHY FROM 18 NOVEMBER 308 TO THE BEGINNING OF MAY 311
After the death of Severus it isn't Constantine who moves up in the
higher title. In the emperor's conference of Carnutum Diocletian
Licinius will be the new Augustus of the West.
5. TETRARCHY FROM MAY 311
After the death of
Galerius he was succeeded by
Maximinus Daia in the
rank of an Augustus of the East, but is crowded by Licinius, who wants
to have the status of the senior Augustus. Maximinus appoints firstly
no new Caesar, although it was assumed, that this position should
later on be filled out with the son of Severus,
Flavius Severianus ,
or at least he was scheduled for this position.
(6.) TETRARCHY AFTER 8 OCTOBER 316 TO THE END OF 316
Shortly before the turn of the year 316/317 for a short-term exists
the situation, that both Augusti Constantin and
Licinius appoint again
a Caesar. If both want to give the appearance of a continuity of the
Tetrarchy is also unclear as the date stamping which could also be the
turn of the year 314/315.
(7.) TETRARCHY FROM 1 MARCH 317 TO 18 SEPTEMBER 324
The tetrarchic system is at its end, the dynastic system has won.
Both Augusti appoint their own sons to co-emperors, Constantin even
two of his sons. Short before of his end
Licinius appoints the General
Martinianus on 3. July 324 to his co-emperor.
Crispus and Constantine II
Although the tetrarchic system as such only lasted until 313 CE, many
aspects of it survived. The fourfold regional division of the empire
continued in the form of Praetorian prefectures , each of which was
overseen by a praetorian prefect and subdivided into administrative
dioceses , and often reappeared in the title of the military
supra-provincial command assigned to a magister militum .
The pre-existing notion of consortium imperii , the sharing of
imperial power, and the notion that an associate to the throne was the
designated successor (possibly conflicting with the notion of
hereditary claim by birth or adoption), was to reappear repeatedly.
The idea of the two halves, the east and the west, re-emerged and
eventually resulted in the permanent de facto division into two
separate Roman empires after the death of
Theodosius I , though it is
important to remember that the empire was never formally divided, the
emperors of the eastern and western halves legally ruling as one
imperial college until the fall of Rome's western empire left
Byzantium, the "second Rome", sole direct heir.
Part of a series of articles on
Divine right of kings
Divine right of kings
Mandate of Heaven
Mandate of Heaven
* Birth of the
* Foundation of the Ottoman Empire
First French Empire
First French Empire
Second French Empire
Second French Empire
* German unification
5 October 1910 Revolution
5 October 1910 Revolution
* Proclamation of the Republic in Brazil
Siamese revolution of 1932
Siamese revolution of 1932
* Birth of the Italian Republic
Spanish transition to democracy
Spanish transition to democracy
Nepalese Civil War
* Tetrarchies in the ancient world existed in both
northern Greece) and
Galatia (in central
Asia Minor ; including
Lycaonia ) as well as among the British
* The constellation of Jewish principalities in the Herodian kingdom
Judea was known as a tetrarchy; see
Tetrarchy (Judea) .
* In the novel
The Lion, the Witch and the Wardrobe
The Lion, the Witch and the Wardrobe , the Pevensie
siblings rule Narnia as a tetrarchy of two kings and two queens.
Notitia dignitatum , a later document from the imperial chancery
* ^ Historian David Potter translates the term as "gang of four ".
See idem., Constantine the Emperor (Oxford: Oxford University Press,
* ^ Qtd. and tr. Leadbetter, Galerius, 3.
* ^ Leadbetter, Galerius, 3.
* ^ Leadbetter, Galerius, 3–4.
* ^ The chronology has been thoroughly established by Kolb,
Diocletian, and Kuhoff, Diokletian.
* Barnes, Timothy D. (1984). Constantine and Eusebius. Harvard
University Press . ISBN 0-674-16531-4 .
* Bowman, Alan (2005). The Cambridge Ancient History Volume 12, The
Crisis of Empire, AD 193–337.
Cambridge University Press
Cambridge University Press . ISBN
* Corcoran, Simon (2000). The Empire of the Tetrarchs, Imperial
Pronouncements and Government AD 284–324.
Oxford University Press
Oxford University Press .
ISBN 0-19-815304-X .
* Kolb, Frank (1987).
Diocletian und die Erste Tetrarchie.
Improvisation oder Experiment in der Organisation monarchischer
Herrschaft?, Berlin: de Gruyter. ISBN 978-3-11-010934-4
* Kuhoff, Wolfgang (2001). Diokletian und die Epoche der Tetrarchie.
Das römische Reich zwischen Krisenbewältigung und Neuaufbau
(284–313 n. Chr.), Frankfurt am Main: Lang. ISBN 3-631-36792-9
* Leadbetter, William Lewis (2009).
Galerius and the Will of
Diocletian. London and New York: Routledge.
* Rees, Roger (2004).
Diocletian and the Tetrarchy. Edinburgh
University Press. ISBN 0-7486-1661-6 .
Wikimedia Commons has media related to TETRARCHY .
* A detailed chronology of the tetrarchy from Diocletian