The
Roman emperors were the rulers of 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 ...
from the granting of the name and title ''
Augustus
Gaius Julius Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian (), was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in A ...
'' to
Octavian
Gaius Julius Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian (), was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in ...
by the
Roman Senate
The Roman Senate () was the highest and constituting assembly of ancient Rome and its aristocracy. With different powers throughout its existence it lasted from the first days of the city of Rome (traditionally founded in 753 BC) as the Sena ...
in 27 BC onward. Augustus maintained a facade of Republican rule, rejecting monarchical titles but calling himself ''
princeps senatus'' (first man of the
Senate
A senate is a deliberative assembly, often the upper house or chamber of a bicameral legislature. The name comes from the ancient Roman Senate (Latin: ''Senatus''), so-called as an assembly of the senior (Latin: ''senex'' meaning "the el ...
) and ''princeps civitatis'' (first citizen of the state). The title of Augustus was conferred on his successors to the imperial position, and emperors gradually grew more monarchical and authoritarian.
The style of government instituted by Augustus is called the
Principate
The Principate was the form of imperial government of the Roman Empire from the beginning of the reign of Augustus in 27 BC to the end of the Crisis of the Third Century in AD 284, after which it evolved into the Dominate. The principate was ch ...
and continued until the late third or early fourth century. The modern word "emperor" derives from the title ''
imperator
The title of ''imperator'' ( ) originally meant the rough equivalent of ''commander'' under the Roman Republic. Later, it became a part of the titulature of the Roman Emperors as their praenomen. The Roman emperors generally based their autho ...
'', that was granted by an army to a successful general; during the initial phase of the empire, the title was generally used only by the ''
princeps
''Princeps'' (plural: ''Principes'') is a Latin word meaning "first in time or order; the first, foremost, chief, the most eminent, distinguished, or noble; the first person". As a title, ''Princeps'' originated in the Roman Republic wherein the ...
''. For example, Augustus's official name was ''Imperator Caesar Divi Filius Augustus''. The territory under command of the emperor had developed under the period of the
Roman Republic
The Roman Republic ( ) was the era of Ancient Rome, classical Roman civilisation beginning with Overthrow of the Roman monarchy, the overthrow of the Roman Kingdom (traditionally dated to 509 BC) and ending in 27 BC with the establis ...
as it invaded and occupied much of
Europe
Europe is a continent located entirely in the Northern Hemisphere and mostly in the Eastern Hemisphere. It is bordered by the Arctic Ocean to the north, the Atlantic Ocean to the west, the Mediterranean Sea to the south, and Asia to the east ...
and portions of
North Africa
North Africa (sometimes Northern Africa) is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region. However, it is sometimes defined as stretching from the Atlantic shores of t ...
and the
Middle East
The Middle East (term originally coined in English language) is a geopolitical region encompassing the Arabian Peninsula, the Levant, Turkey, Egypt, Iran, and Iraq.
The term came into widespread usage by the United Kingdom and western Eur ...
. Under the republic, the
Senate and People of Rome authorized provincial governors, who answered only to them, to rule regions of the empire. The chief magistrates of the republic were two
consuls
A consul is an official representative of a government who resides in a foreign country to assist and protect citizens of the consul's country, and to promote and facilitate commercial and diplomatic relations between the two countries.
A consu ...
elected each year; consuls continued to be elected in the imperial period, but their authority was subservient to that of the emperor, who also controlled and determined their election. Often, the emperors themselves, or close family, were selected as consul.
After the
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 ...
,
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 ...
increased the authority of the emperor and adopted the title ''dominus noster'' (our lord). The rise of powerful
barbarian tribes along the borders of the empire, the challenge they posed to the defense of far-flung borders as well as an unstable imperial succession led Diocletian to divide the administration of the Empire geographically with a co-''augustus'' in 286. In 330,
Constantine the Great
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 emperor who accepted Christianity, established a second capital in
Byzantium
Byzantium () or Byzantion () was an ancient Greek city in classical antiquity that became known as Constantinople in late antiquity and Istanbul today. The Greek name ''Byzantion'' and its Latinization ''Byzantium'' continued to be used as a n ...
, which was renamed
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 ...
. Historians consider the
Dominate
The Dominate is a periodisation of the Roman Empire during late antiquity
Late antiquity marks the period that comes after the end of classical antiquity and stretches into the onset of the Early Middle Ages. Late antiquity as a period was p ...
period of the empire to have begun with either Diocletian or Constantine, depending on the author. For most of the period from 286 to 480, there was more than one recognized senior emperor, with the division usually based on geographic regions. This division became permanent after the death of
Theodosius I
Theodosius I ( ; 11 January 347 – 17 January 395), also known as Theodosius the Great, was Roman emperor from 379 to 395. He won two civil wars and was instrumental in establishing the Nicene Creed as the orthodox doctrine for Nicene C ...
in 395, which historians have traditionally dated as the division between the
Western Roman Empire
In modern historiography, the Western Roman Empire was the western provinces of the Roman Empire, collectively, during any period in which they were administered separately from the eastern provinces by a separate, independent imperial court. ...
and the
Eastern Roman 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 the events that caused the fall of the Western Roman E ...
. However, formally the Empire remained a single polity, with separate co-emperors in the separate courts.
The
fall of the Western Roman Empire
The fall of the Western Roman Empire, also called the fall of the Roman Empire or the fall of Rome, was the loss of central political control in the Western Roman Empire, a process in which the Empire failed to enforce its rule, and its vast ...
is dated either from the ''
de facto'' date of 476, when
Romulus Augustulus
Romulus Augustus (after 511), nicknamed Augustulus, was Roman emperor of the Western Roman Empire, West from 31 October 475 until 4 September 476. Romulus was placed on the imperial throne while still a minor by his father Orestes (father of Ro ...
was deposed by the Germanic
Herulians led by
Odoacer, or the ''
de jure
In law and government, ''de jure'' (; ; ) describes practices that are officially recognized by laws or other formal norms, regardless of whether the practice exists in reality. The phrase is often used in contrast with '' de facto'' ('from fa ...
'' date of 480, on the death of
Julius Nepos
Julius Nepos (died 9 May 480), or simply Nepos, ruled as Roman emperor of the West from 24 June 474 to 28 August 475. After losing power in Italy, Nepos retreated to his home province of Dalmatia, from which he continued to claim the western i ...
, when Eastern emperor
Zeno
Zeno may refer to:
People
* Zeno (name), including a list of people and characters with the given name
* Zeno (surname)
Philosophers
* Zeno of Elea (), philosopher, follower of Parmenides, known for his paradoxes
* Zeno of Citium (333 – 264 B ...
ended recognition of a separate Western court. Historians typically refer to the empire in the centuries that followed as 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 ...
", governed by the Byzantine emperors. Given that "Byzantine" is a later
historiographical
Historiography is the study of the methods used by historians in developing history as an academic discipline. By extension, the term ":wikt:historiography, historiography" is any body of historical work on a particular subject. The historiog ...
designation and the inhabitants and emperors of the empire continually maintained
Roman identity, this designation is not used universally and continues to be a subject of specialist debate. Under
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 sixth century, a large portion of the western empire was retaken, including Italy, Africa, and part of Spain. Over the course of the centuries thereafter, most of the imperial territories were lost, which eventually restricted the empire to
Anatolia
Anatolia (), also known as Asia Minor, is a peninsula in West Asia that makes up the majority of the land area of Turkey. It is the westernmost protrusion of Asia and is geographically bounded by the Mediterranean Sea to the south, the Aegean ...
and the
Balkans
The Balkans ( , ), corresponding partially with the Balkan Peninsula, is a geographical area in southeastern Europe with various geographical and historical definitions. The region takes its name from the Balkan Mountains that stretch throug ...
. The line of emperors continued until the death of
Constantine XI Palaiologos
Constantine XI Dragases Palaiologos or Dragaš Palaeologus (; 8 February 140429 May 1453) was the last reigning List of Byzantine emperors, Byzantine emperor from 23 January 1449 until his death in battle at the fall of Constantinople on 29 M ...
at the
fall of Constantinople
The Fall of Constantinople, also known as the Conquest of Constantinople, was the capture of Constantinople, the capital of the Byzantine Empire by the Ottoman Empire. The city was captured on 29 May 1453 as part of the culmination of a 55-da ...
in 1453, when the remaining territories were conquered by the
Ottoman Turks
The Ottoman Turks () were a Turkic peoples, Turkic ethnic group in Anatolia. Originally from Central Asia, they migrated to Anatolia in the 13th century and founded the Ottoman Empire, in which they remained socio-politically dominant for the e ...
led by Sultan
Mehmed II
Mehmed II (; , ; 30 March 14323 May 1481), commonly known as Mehmed the Conqueror (; ), was twice the sultan of the Ottoman Empire from August 1444 to September 1446 and then later from February 1451 to May 1481.
In Mehmed II's first reign, ...
. In the aftermath of the conquest, Mehmed II proclaimed himself ''kayser-i Rûm'' ("
''Caesar'' of the Romans"), thus claiming to be the new emperor,
a claim maintained by succeeding sultans. Competing claims of
succession to the Roman Empire have also been forwarded by various other states and empires, and by numerous
later pretenders.
Legitimacy

While the imperial government of 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 ...
was rarely called into question during its five centuries in the west and fifteen centuries in the east, individual emperors often faced unending challenges in the form of usurpation and perpetual civil wars. From the rise of
Augustus
Gaius Julius Caesar Augustus (born Gaius Octavius; 23 September 63 BC – 19 August AD 14), also known as Octavian (), was the founder of the Roman Empire, who reigned as the first Roman emperor from 27 BC until his death in A ...
, the first Roman emperor, in 27 BC to the
sack of Rome in AD 455, there were over a hundred usurpations or attempted usurpations (an average of one usurpation or attempt about every four years). From the murder of
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 ...
in 192 until the fifth century, there was scarcely a single decade without succession conflicts and civil war. Very few emperors died of natural causes, with
regicide in practical terms having become the expected end of a Roman emperor by
late antiquity
Late antiquity marks the period that comes after the end of classical antiquity and stretches into the onset of the Early Middle Ages. Late antiquity as a period was popularized by Peter Brown (historian), Peter Brown in 1971, and this periodiza ...
. The distinction between a usurper and a legitimate emperor is a blurry one, given that a large number of emperors that were commonly considered legitimate began their rule as usurpers, revolting against the previous legitimate emperor.
True legitimizing structures and theories were weak, or wholly absent in the Roman Empire, and there were no true objective legal criteria for being acclaimed emperor beyond acceptance by the
Roman army
The Roman army () served ancient Rome and the Roman people, enduring through the Roman Kingdom (753–509 BC), the Roman Republic (509–27 BC), and the Roman Empire (27 BC–AD 1453), including the Western Roman Empire (collapsed Fall of the W ...
. Dynastic succession was not legally formalized, but also not uncommon, with powerful rulers sometimes succeeding in passing power on to their children or other relatives. While dynastic ties could bring someone to the throne, they were not a guarantee that their rule would not be challenged. With the exception of
Titus
Titus Caesar Vespasianus ( ; 30 December 39 – 13 September AD 81) was Roman emperor from 79 to 81. A member of the Flavian dynasty, Titus succeeded his father Vespasian upon his death, becoming the first Roman emperor ever to succeed h ...
(79–81; son of
Vespasian
Vespasian (; ; 17 November AD 9 – 23 June 79) was Roman emperor from 69 to 79. The last emperor to reign in the Year of the Four Emperors, he founded the Flavian dynasty, which ruled the Empire for 27 years. His fiscal reforms and consolida ...
), no son of an emperor who ruled after the death of his father died a natural death until
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 ...
in 337. Control of
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, ...
itself and approval of the
Roman Senate
The Roman Senate () was the highest and constituting assembly of ancient Rome and its aristocracy. With different powers throughout its existence it lasted from the first days of the city of Rome (traditionally founded in 753 BC) as the Sena ...
held some importance as legitimising factors, but were mostly symbolic. Emperors who began their careers as usurpers had often been deemed
public enemies by the senate before they managed to take the city. Emperors did not need to be acclaimed or crowned in Rome itself, as demonstrated in the
Year of the Four Emperors (69), when claimants were crowned by armies in the
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, and the senate's role in legitimising emperors had almost faded into insignificance by the
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 ...
(235–285). By the end of the third century, Rome's importance was mainly ideological, with several emperors and usurpers even beginning to place their court in other cities in the empire, closer to the imperial frontier.
Common methods used by emperors to assert claims of legitimacy, such as proclamation by the army, blood connections (sometimes fictitious) to past emperors, wearing imperial regalia, distributing one's own coins or statues and claims to pre-eminent virtue through propaganda, were pursued just as well by many usurpers as they were by legitimate emperors. There were no constitutional or legal distinctions that differentiated legitimate emperors and usurpers. In ancient Roman texts, the differences between emperors and "tyrants" (the term typically used for usurpers) is often a moral one (with the tyrants ascribed wicked behaviour) rather than a legal one. Typically, the actual distinction was whether the claimant had been victorious or not. In the ''
Historia Augusta
The ''Historia Augusta'' (English: ''Augustan History'') is a late Roman collection of biographies, written in Latin, of the Roman emperors, their junior colleagues, Caesar (title), designated heirs and Roman usurper, usurpers from 117 to 284. S ...
'', an ancient Roman collection of imperial biographies, the usurper
Pescennius Niger
Gaius Pescennius Niger (c. 135 – 194) was a Roman usurper from 193 to 194 during the Year of the Five Emperors. He claimed the imperial throne in response to the murder of Pertinax and the elevation of Didius Julianus, but was defeated by a ...
(193–194) is expressly noted to only be a tyrant because he was defeated by
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 ...
(193–211). This is also followed in modern
historiography
Historiography is the study of the methods used by historians in developing history as an academic discipline. By extension, the term ":wikt:historiography, historiography" is any body of historical work on a particular subject. The historiog ...
, where, in the absence of constitutional criteria separating them, the main factor that distinguishes usurpers from legitimate Roman emperors is their degree of success. What makes a figure who began as a usurper into a legitimate emperor is typically either that they managed to gain the recognition from a more senior, legitimate emperor, or that they managed to defeat a more senior, legitimate emperor and seize power from them by force.
List inclusion criteria
Given that a concept of constitutional legitimacy was irrelevant in the Roman Empire, and emperors were only 'legitimate' in so far as they were able to be accepted in the wider empire, this list of emperors operates on a collection of inclusion criteria:
* Imperial claimants whose power across the empire became, or from the beginning was, absolute and who ruled undisputed are treated as legitimate emperors. From 286 onward, when imperial power was usually divided among two colleagues in the east and west, control over the respective half is sufficient even if a claimant was not recognized in the other half, such as was the case for several of the last few emperors in the west.
* Imperial claimants who were proclaimed emperors by another, legitimate, senior emperor, or who were recognized by a legitimate senior emperor, are treated as legitimate emperors. Many emperors ruled alongside one or various joint-emperors. However, and specially from the 4th century onwards, most of these were children who never ruled in their own right. Scholars of the later Empire always omit these rulers, but the same is not always applied during the early Empire. For the purposes of consistency, later senior emperors' tenures as junior co-emperors are not counted as part of their reign. The list also gives all co-emperors their own entry only up to the 4th century.
* Imperial claimants who achieved the recognition of the Roman Senate, especially in times of uncertainty and civil war, are, due to the senate's nominal role as an elective body, treated as legitimate emperors.
[; ] In later times, especially when emperors ruled from other cities, this criterion defaults to the possession and control of Rome itself. In the later eastern empire, possession of the capital of
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 ...
was an essential element of imperial legitimacy.
In the case of non-dynastic emperors after or in the middle of the rule of a dynasty, it is customary among historians to group them together with the rulers of said dynasty, an approach that is followed in this list. Dynastic breaks with non-dynastic rulers are indicated with thickened horizontal lines.
Principate (27 BC – AD 284)
Julio-Claudian dynasty (27 BC – AD 68)
Year of the Four Emperors (68–69)
Flavian dynasty (69–96)
Nerva–Antonine dynasty (96–192)
Year of the Five Emperors (193)
:
Severan dynasty (193–235)
Crisis of the Third Century (235–285)
Dominate (284–476)
Tetrarchy (284–324)
Constantinian dynasty (306–363)
Valentinianic dynasty (364–392)
Theodosian dynasty (379–457)
Last western emperors (455–476)
Later Eastern emperors (457–1453)
Leonid dynasty (457–518)
Justinian dynasty (518–602)
Heraclian dynasty (610–695)
Twenty Years' Anarchy (695–717)
Isaurian (Syrian) dynasty (717–802)
Nikephorian dynasty (802–813)
Amorian dynasty (820–867)
Macedonian dynasty (867–1056)
Doukas dynasty (1059–1078)
Komnenos dynasty (1081–1185)
Angelos dynasty (1185–1204)
Laskaris dynasty (1205–1261)
:
Palaiologos dynasty (1259–1453)
Other claims to the Roman imperial title
See also
*
List of Roman empresses – for a list of the consorts of the Roman emperors
*
Burial places of Roman emperors – for a list of the burial places of the Roman emperors
*
List of Roman consuls – for a list of the consuls who held power during the Roman Republic and who continued to be appointed in imperial times
*
List of Roman dictators – for a list of dictators during the Roman Republic
*
List of Roman dynasties – for a list of the many dynasties that ruled the Roman Empire
*
Family tree of Roman emperors – for a concise family tree of emperors and their immediate family (27 BC–518 AD)
*
Family tree of Byzantine emperors – for a concise family tree of emperors and their immediate family (337–1453)
Notes
References
Citations
Works cited
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Cited links
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Further reading
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External links
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The Rulers of the Roman Empire. ''
De Imperatoribus Romanis''
Chronology of Roman emperorsby Ian Mladjov
{{DEFAULTSORT:List Of Roman emperors
*
Government of the Roman Empire
Roman emperors
Emperors
The word ''emperor'' (from , via ) can mean the male ruler of an empire. ''Empress'', the female equivalent, may indicate an emperor's wife ( empress consort), mother/grandmother (empress dowager/ grand empress dowager), or a woman who rule ...