Not to be confused with King of the Romans or Holy Roman Emperor. This article is about the nature of the imperial dignity, and its dynastic development throughout the history of the Empire. For a discussion of the emperor's claimed divine status, see Imperial cult (Ancient Rome). For a more comprehensive listing of names of emperors, see list of Roman Emperors. This article needs additional citations for verification. Please help improve this article by adding reliable references. Unsourced material may be challenged and removed. (January 2010) Emperor of the Roman Empire Former Monarchy Imperial Vexillum Augustus First monarch Augustus Last monarch Theodosius I (Unified or Classical), Romulus Augustus (Western), Constantine XI (Eastern) Style His Majesty Monarchy started 27 BC Monarchy ended AD 395 (Unified or Classical), AD 476 (Western), AD 1453 (Eastern) Current pretender None The Roman Emperor was the ruler of the Roman State during the imperial period (starting at about 27 BC). The Romans had no single term for the office: Latin titles such as imperator (from which English emperor ultimately derives), augustus, caesar and princeps were all associated with it. In practice, the emperor was supreme ruler of Rome and supreme commander of the Roman legions. Since the Roman Republic was constituted on an profoundly non-royalist basis, Rome theoretically remained a republic, the res publica (literally, thing of the people), and the emperor's status was that of primus inter pares—first among equals. The emperor assumed several offices of the Republic at the same time, and thus consolidated absolute power vested in his person in all but name. This legal fiction became increasingly meaningless as the emperors consolidated their power. However, it was maintained at least to a ceremonial degree until the very end of the Roman Empire. The Western Roman Empire met its end in 476 and the Eastern Roman Empire in 1453. The only monarchical principle never instituted formally was that of familial succession, as the office remained an elective one, in theory and quite often in practice. The right of election vaguely belonged to the Senate, and/or the people, and/or the army, and the legitimacy of such an election was judged a posteriori only by whether it was successful or not. From the religious standpoint, emperors, in addition to their pontifical office, were also given divine status: initially after their death, but later from their accession. As Christianity prevailed over paganism, the emperor's religious status changed to that of Christ's regent on earth, and the Empire's status was seen as part of God's plan to Christianize the world. Contents 1 Overview 1.1 Imperator 1.2 Princeps 1.3 First Roman emperor 1.4 Fall of the West 1.5 Survival of the Roman Empire in the East 1.6 Last Roman Emperor 2 Pretenders 2.1 New Western lineage 2.2 New Eastern lineage 3 Titles and positions 3.1 Powers 4 Lineages and epochs 4.1 Principate 4.2 Crisis of the Third Century 4.3 Dominate 4.4 Late empire 5 See also 6 Notes 7 Further reading 8 External links // Overview Ancient Rome This article is part of the series: Politics and government of Ancient Rome Periods Roman Kingdom 753 BC – 509 BC Roman Republic 508 BC – 27 BC Roman Empire 27 BC – AD 1453 Principate Western Empire Dominate Eastern Empire Roman Constitution Constitution of the Kingdom Constitution of the Republic Constitution of the Empire Constitution of the Late Empire History of the Constitution Senate Legislative Assemblies Executive Magistrates Ordinary Magistrates Consul Praetor Quaestor Promagistrate Aedile Tribune Censor Governor Extraordinary Magistrates Dictator Magister Equitum Consular tribune Rex Triumviri Decemviri Titles and Honours Emperor Legatus Dux Officium Praefectus Vicarius Vigintisexviri Lictor Magister militum Imperator Princeps senatus Pontifex Maximus Augustus Caesar Tetrarch Precedent and Law Roman Law Imperium Mos maiorum Collegiality Roman citizenship Auctoritas Cursus honorum senatus consultum (senatus consultum ultimum) Other countries · Atlas Politics portal view · talk · Rome used no single constitutional office, title or rank exactly equivalent to the English title "Roman Emperor". Romans of the Imperial era used several titles to denote their emperors, and all were associated with the pre-Imperial, Republican era. "Roman Emperor" is a convenient shorthand used by historians to express the complex nature of the person otherwise known as princeps - itself a republican honorific.

The emperor's legal authority derived from an extraordinary concentration of individual powers and offices extant in the Republic rather than from a new political office; emperors were regularly elected to the offices of consul and censor. Among their permanent privileges were the traditional Republican title of princeps senatus (leader of the Senate) and the religious office of pontifex maximus (chief priest of Roman state). Every emperor held the latter office and title until Gratian surrendered it in 382 AD to St. Siricius; it eventually became an auxiliary honor of the Bishop of Rome. These titles and offices conferred great personal prestige (dignitas) but the basis of an emperor's powers derived from his auctoritas: this assumed his greater powers of command (imperium maius) and tribunician power (tribunicia potestas) as personal qualities, independent of his public office. As a result, he formally outranked provincial governors and ordinary magistrates. He had the right to enact or revoke sentences of capital punishment, was owed the obedience of private citizens (privati) and by the terms of the ius auxiliandi could save any plebeian from any patrician magistrate's decision. He could veto any act or proposal of any magistrate, including the tribunes of the people (ius intercedendi or ius intercessionis). His person was held to be sacrosanct. Roman magistrates on official business were expected to wear the form of toga associated with their office; different togas were worn by different ranks; senior magistrates had the right to togas bordered with purple. A triumphal imperator of the Republic had the right to wear the toga picta (of solid purple, richly embroidered) for the duration of the triumphal rite. During the Late Republic, the most powerful had this right extended. Pompey and Caesar are both thought to have worn the triumphal toga and other triumphal dress at public functions. Later Emperors were distinguished by wearing togae purpurae, purple togas; hence the phrase "to don the purple" for the assumption of imperial dignity. The titles customarily associated with the imperial dignity are imperator ("commander", lit. "one who prepares against"), which emphasizes the emperor's military supremacy and is the source of the English word emperor; caesar, which was originally a name but it came to be used for the designated heir (as Nobilissimus Caesar, "Most Noble Caesar") and was retained upon accession. The ruling emperor's title was the descriptive augustus ("majestic" or "venerable", which had tinges of the divine), which was adopted upon accession. In Greek, these three titles were rendered as autokratōr, kaisar, and augustos or sebastos respectively). In Diocletian's Tetrarchy, the traditional seniorities were maintained: Augustus was reserved for the two senior emperors and Caesar for the two junior emperors - each delegated a share of power and responsibility but each an emperor-in-waiting, should anything befall his senior. As princeps senatus (lit., "first man of the senate"), the emperor could receive foreign embassies to Rome; some emperors (such as Tiberius) are known to have delegated this task to the Senate. In modern terms these early emperors would tend to be identified as chiefs of state. The office of princeps senatus, however, was not a magistracy and did not own imperium. At some points in the empire's history, the emperor's power was nominal; powerful praetorian prefects, masters of the soldiers and on a few occasions, other members of the Imperial family including Imperial mothers and grandmothers acted as the true source of power. Imperator Main article: Imperator The title imperator dates back to the Roman Republic, when a victorious commander could be hailed as imperator in the field by his troops. The Senate could then award (or withhold) the extraordinary honour of a triumph; the triumphal commander retained the title until the end of his magistry.1 Roman tradition held the first triumph as that of Romulus but the first attested recipient of the title imperator in a triumphal context is Aemilius Paulus in 189 BC1. It was a title held with great pride: Pompey was hailed imperator more than once, as was Sulla, but it was Julius Caesar who first used it permanently - according to Dio, this was a singular and excessive form of flattery granted by the Senate, passed to Caesar's adopted heir along with his name and virtually synonymous with it.2

In 38 BC Agrippa refused a triumph for his victories under Octavian's command and this precedent established the rule that the princeps should assume both the salutation and title of imperator. It seems that from then on Octavian (later first emperor Augustus) used imperator as a praenomen (Imperator Caesar not Caesar imperator). From this the title came to denote the supreme power and was commonly used in that sense. Otho was the first to imitate Augustus but only with Vespasian did imperator (emperor) become the official title by which the ruler of the Roman Empire was known. Princeps The word princeps (plural principes), meaning "first", was a republican term used to denote the leading citizen(s) of the state. It was a purely honorific title with no attached duties or powers. It was the title most preferred by Caesar Augustus as its use implies only primacy, as opposed to another of his titles, imperator, which implies dominance. Princeps, because of its republican connotation, was most commonly used to refer to the emperor in Latin (although the emperor's actual constitutional position was essentially "pontifex maximus with tribunician power and imperium superseding all others") as it was in keeping with the facade of the restored republic; the Greek word basileus ("king") was modified to be synonymous with emperor (and primarily came into favour after the reign of Heraclius) as the Greeks had no republican sensibility and openly viewed the emperor as a monarch. In the era of Diocletian and beyond, princeps fell into disuse and was replaced with dominus ("lord");citation needed later emperors used the formula Imperator Caesar NN. Pius Felix (Invictus) Augustus. NN representing the individual's personal name, Pius Felix, meaning "Pious and Blest", and Invictus meaning "undefeated". The use of princeps and dominus broadly symbolise the differences in the empire's government, giving rise to the era designations "Principate" and "Dominate". First Roman emperor Statue of Caesar Augustus, c. 30 BC–20 BC; this statue is located in the Louvre At the end of the Roman Republic no new, and certainly no single title indicated the individual who held supreme power. Insofar as emperor could be seen as the English translation of imperator, then Julius Caesar had been an emperor, like several Roman generals before him. Instead, by the end of the civil wars in which Julius Caesar had led his armies, it became clear on the one hand that there was certainly no consensus to return to the old-style monarchy, and that on the other hand the situation where several officials, bestowed with equal power by the senate, fought one another had to come to an end. Julius Caesar, then Octavian after him, accumulated offices and titles of the highest importance in the Republic, making the power attached to these offices permanent, and preventing anyone with similar aspirations from accumulating or maintaining power for themselves. However, Julius Caesar, unlike those after him, did so without the Senate's vote and approvalcitation needed. Julius Caesar held the Republican offices of consul four times and dictator five times, was appointed dictator in perpetuity (dictator perpetuo) in 45 BC and had been "pontifex maximus" for several decades. He gained these positions by senatorial consent. By the time of his assassination in 44 BC he was the most powerful man in Rome. In his will, Caesar appointed his adopted son Octavian as his heir. On Caesar's death, Octavian inherited his adoptive father's property and lineage, the loyalty of most of his allies and - again through a formal process of senatorial consent – an increasing number of the titles and offices that had accrued to Caesar. A decade after Caesar's death, Octavian's victory over his erstwhile ally Mark Antony at Actium put an end to any effective opposition and confirmed Octavian's supremacy. In 27 BC, Octavian appeared before the Senate and offered to retire from active politics and government; the Senate not only requested he remain, but increased his powers and made them lifelong, awarding him the title of Augustus (the elevated or divine one, somewhat less than a god but approaching divinity). Octavian stayed in office till his death; the sheer breadth of his superior powers as princeps and permanent imperator of Rome's armies guaranteed the peaceful continuation of what nominally remained a republic. His "restoration" of powers to the Senate and the people of Rome was a demonstration of his auctoritas and pious respect for tradition.

Even at Augustus' death, some later historians such as Tacitus would say that the true restoration of the Republic might have been possible. Instead, Augustus actively prepared his adopted son Tiberius to be his replacement and pleaded his case to the Senate for inheritance through merit. The Senate disputed the issue but eventually confirmed Tiberius as princeps. Once in power, Tiberius took considerable pains to observe the forms and day-to-day substance of republican government. The historians of the 1st centuries observed the dynastic continuity: if a hereditary monarchy-not-by-kings existed after the republic, it had started with Julius Caesar. In this sense Suetonius wrote of The Twelve Caesars, meaning the emperors from Julius Caesar to the Flavians included (where, after Nero, the inherited name had turned into a title), and emperors adopted themselves into an Imperial lineage. Fall of the West By the end of the 3rd century, the Roman Empire was split into Western and an Eastern parts, each with its own augustis (and/or caesares). In the West, which included Rome, the succession of emperors ended in the year 476 when the last Western emperor, Romulus Augustus, was deposed by the Germanic King Odoacer, although many maintain that Julius Nepos was the last emperor and that the Eastern emperor Zeno decided not to appoint a new emperor in the West. This is generally accepted to be the end of Antiquity and the beginning the Early Middle Ages also known as the Dark Ages. However, Roman rule had disintegrated somewhat earlier in the century as a result of Germanic invasions which had overrun all of the territory that had belonged to the western half of the Roman Empire. In the east however, the Eastern Roman Empire survived until 1453. Although the Greek-speaking inhabitants were Romaioi (Ῥωμαῖοι), many in Western Europe referred to the political entity as the "Greek Empire". Today it is known as the Byzantine Empire, as its capital was once the city of Byzantium, which had been massively expanded and re-named Constantinople in honour of the emperor Constantine the Great, and is now known as the Turkish city of Istanbul. Survival of the Roman Empire in the East Imaginary portrait of Constantine XI The last Roman emperor The line of Roman emperors in the Eastern Roman Empire continued unbroken until the fall of Constantinople in 1453 under Constantine XI Palaiologos. These emperors eventually normalized the imperial dignity into the modern conception of an emperor, incorporated it into the constitutions of the state, and adopted the aforementioned title Basileus kai autokratōr Rhomaiōn ("Emperor and Autocrat of the Romans"). These emperors ceased to use Latin as the language of state after Heraclius. Historians have customarily treated the state of these later Eastern emperors under the name "Byzantine Empire", though Byzantine is not a term that the Byzantines ever used to describe themselves. Last Roman Emperor Main article: Constantine XI Constantine XI Palaiologos was the last reigning Roman Emperor. A member of the Palaiologos dynasty, he ruled the feeble remnant of the East Roman (Byzantine) Empire from 1449 until his death in 1453 defending its capital Constantinople. He was born in Mystra3 as the eighth of ten children of Manuel II Palaiologos and Helena Dragaš, the daughter of the Serbian prince Constantine Dragaš of Kumanovo. He spent most of his childhood in Constantinople under the supervision of his parents. During the absence of his older brother in Italy, Constantine was regent in Constantinople from 1437-1440. Before the beginning of the siege, Mehmed II made an offer to Constantine XI. In exchange for the surrender of Constantinople, the emperor's life would be spared and he would continue to rule in Mystra. Constantine refused this offer. Instead he led the defense of the city and took an active part in the fighting along the land walls. At the same time, he used his diplomatic skills to maintain the necessary unity between the Genovese, Venetian, and Byzantine troops. As the city fell on May 29, 1453, Constantine is said to have remarked: "The city is fallen but I am alive." Realizing that the end had come, he reportedly discarded his purple cloak and led his remaining soldiers into a final charge, in which he was killed. With his death, Roman imperial succession came to an end, almost 1500 years after Augustus.

After the fall of Constantinople, Thomas Palaiologos, brother of Constantine IX, was elected Emperor and tried to organize the remaining forces. His rule came to an end after the fall of the last major Byzantine city, Corinth. He then moved in Italy and continued to be recognized as Eastern Emperor by the Christian powers. His son Andreas Palaiologos continued claims on the Byzantine throne until he sold the title to Ferdinand of Aragon and Isabella of Castile, the grandparents of Holy Roman Emperor Charles V. Pretenders New Western lineage Charles V was the last man to be crowned Roman Emperor and to celebrate triumph in Rome The concept of the Roman Empire was renewed in the West with the coronation of the king of the Franks, Charlemagne, as Roman emperor by the Pope on Christmas Day, 800. This line of Roman emperors was actually generally Germanic rather than Roman, but maintained their Roman-ness as a matter of principle. These emperors used a variety of titles (most frequently "Imperator Augustus") before finally settling on Imperator Romanus Electus ("Elected Roman Emperor"). Historians customarily assign them the title "Holy Roman Emperor", which has a basis in actual historical usage, and treat their "Holy Roman Empire" as a separate institution. To Latin Christians of the time, the Pope was the temporal authority as well as spiritual authority, and as Bishop of Rome he was recognized as having the power to anoint or crown a new Roman emperor. The title of "Western Roman Emperor" was further legitimized when the Eastern Roman emperor at Constantinople recognized Charlemagne as basileus of the west. The last man to hold the title of proper Roman Emperor and to be crowned in Rome was Charles V. All his successors bore only a title of "emperor-elect". Charles V was also the last man to celebrate a triumph in Rome. The line of "emperor-elect" rulers lasted until 1806 when Francis II dissolved the Empire during the Napoleonic Wars. Despite the existence of later potentates styling themselves "Emperor", such as the Napoleons and the heads of the German Reich, this marked the end of the Western Empire. Although there is a living heir to the Habsburg dynasty, as well as a Pope and pretenders to the positions of the electors, and although all the medieval coronation regalia are still preserved in Austria, the legal abolition of all aristocratic prerogatives of the former electors and the imposition of republican constitutions in Germany and Austria removed the potential for a revival of the Holy Roman Empire. New Eastern lineage The "seat" of the eastern lineage was claimed in Russia by the Byzantine-born wife of Ivan III "the Great" who would become the first 'Tsar' or 'Czar' the Russian title for 'Caesar.' He called Russia the third Rome (The capital of the Roman Empire moved to Byzantium by Constantine I, first called 'Nova Roma' and then Constantinople) where some of the relics of the Eastern Orthodox Church and from the Roman Empire were brought. When Mehmed II conquered Constantinople on 29 May 1453, he claimed the title Emperor of the Roman Empire (Kayser-i-Rûm) and protector of the Eastern Orthodox Church. Here, the Caesar title should not be understood as the minor title it had become, but as the glorious title of the emperors of the past, a connotation that had been preserved in Persian and Arabic. The adoption of the title also implied that the Ottoman state considered itself the continuation (by absorption) of the Roman Empire - a view not shared in the West. Acting in his capacity as Caesar of the Roman Empire, Mehmed reinstated the defunct Ecumenical Patriarchate of Constantinople. He appointed the Patriarch of Constantinople Gennadius Scholarius, whom he protected and whose stature he elevated into leader of all the Eastern Orthodox Christians. As emperor of the Romans he laid claim to all Roman territories. However, at the time of the Fall of Constantinople, they extended to little more than the city itself, as well as a small area in Morea (the Peloponnese). Partly to bolster his claim to the title and reunite the Roman Empire, Mehmed II planned to conquer the city of Rome in 1480, but failed. The title of Roman emperor was added to the long list of other titles claimed by the Ottoman sultans. A branch of the Comnenus family who provided emperors from 1081-1185 continued rule over the break-away Empire of Trebizond till 1461. Titles and positions

Although these are the most common offices, titles, and positions, one should note that not all Roman emperors used them, nor were all of them used at the same time in history. The consular and censorial offices especially were not an integral part of the Imperial dignity, and were usually held by persons other than the reigning Emperor. Augustus (also "Αὔγουστος" or "Σεβαστός"), "Majestic" or "Venerable"; an honorific cognomen exclusive to the emperor Αὐτοκράτωρ, Autokrator (lit. "Self-ruler"); Greek title equivalent to imperator i.e. Commander-in-Chief Βασιλεύς (Basileus) , Greek for King, popularly used in the east to refer to the emperor; a formal title of the Roman emperor beginning with Heraclius Caesar (also "Καίσαρ" or "Nobilissimus Caesar"), "Caesar" or "Most Noble Caesar"; an honorific name later used to identify an Emperor-designate Censor, a Republican office with a five year term and one coequal officeholder Consul, the highest magistracy of the Roman Republic with a one year term and one coequal officeholder Dominus, "Lord" or "Master"; an honorific title popular in the Empire's middle history Imperator, "Commander" or "Commander-in-Chief"; a victory title taken on accession to the purple and after a major military victory; the praenomen of most Roman emperors Imperator Destinatus, "Destined to be Emperor"; heir apparent, used by Septimius Severus for Caracalla. Imperium maius, "greater imperium"; absolute power to a degree greater than any other, including power of enacting capital punishment Invictus, "Unconquered"; an honorific title Pater Patriae, "Father of the Fatherland"; an honorific title Pius Felix, "Pious and Blessed" an honorific title Pontifex Maximus, "Supreme Pontiff" or "Chief Priest" (lit. "Greatest Bridgemaker"); a title and office of Republican origin—could not be used by "Catholic" Emperors, while by that time only the pope had a claim on the title of highest religious authority. Princeps, "First Citizen" or "Leading Citizen"; an honorific title denoting the status of the emperor as first among equals Princeps Iuventutis, "Prince of Youth"; an honorific title awarded to a presumptive Emperor-designate Princeps Senatus, "First Man of the Senate" a Republican office with a five year term Tribunitia potestas, "tribunician power"; the powers of a tribune of the people including sacrosanctity and the veto Powers When Augustus established the Princeps, he turned down supreme authority in exchange for a collection of various powers and offices, which in itself was a demonstration of his auctoritas ("authority"). As holding princeps senatus, the emperor declared the opening and closure of each Senate session, declared the Senate's agenda, imposed rules and regulation for the Senate to follow, and met with foreign ambassadors in the name of the Senate. Being pontifex maximus made the emperor the chief administrator of religious affairs, granting him the power to conduct all religious ceremonies, consecrate temples, control the Roman calendar (adding or removing days as needed), appoint the vestal virgins and some flamens, lead the Collegium Pontificum, and summarize the dogma of the Roman religion. While these powers granted the emperor a great deal of personal pride and influence, they did not include legal authority. In 23 BC, Augustus gave the emperorship its legal power. The first was Tribunitia Potestas, or the power of the tribune without actually holding the office. This gave the emperor the ability of personal inviolability (sacrosanctity) and the ability to pardon any civilian for any act, criminal or otherwise. By holding the powers of the tribune, the emperor could prosecute anyone who interfered with the performance of his duties. The emperor's tribuneship granted him the right to convene the Senate at his will and lay proposals before it, as well as the ability to veto any act or proposal by any magistrate, including the tribune of the plebians. Also, as holder of the tribune's power, the emperor would convoke the Council of the People, lay legislation before it, and served as the council's president. But his tribuneship only granted him power within Rome itself. He would need another power to veto the act of governors and that of the consuls while in the provinces. To solve this problem, Augustus managed to have the emperor be given the right to hold two types of imperium. The first being consular imperium while he was in Rome, and imperium maius outside of Rome. While inside the walls of Rome, the reigning consuls and the emperor held equal authority, each being able to veto each other's proposals and acts, with the Emperor holding all of the Consul's powers. But outside of Rome, the emperor outranked the consuls and could veto them without the same effects on himself. Imperium Maius also granted the emperor authority over all the provincial governors, making him the ultimate authority in provincial matters and gave him the supreme command of all of Rome's legions. With Imperium Maius, the emperor was also granted the power to appoint governors of imperial provinces without the interference of the Senate. Also, Imperium Maius granted the emperor the right to veto the governors of the provinces and even the reigning consul while in the provinces. Lineages and epochs

In the listings of Roman emperors below, the common name is given first, followed by the more formal name adopted upon accession to the purple, the name given at birth, and the years of his reign. So-called victory titles and other titles not forming an integral part of the name (Pontifex Maximus, Princeps Senatus, Pater Patriae, &c.) are not listed. Co-emperors are listed in inferior text, along with notes identifying senior emperors who had hitherto served as co-emperors. Following abbreviations are used: A.: Aulus Aug.: Augustus (as a title) C.: Gaius Germ.: Germanicus Imp.: Imperator L.: Lucius M.: Marcus Max.: Maximus Nob.: Nobilissimus P.: Publius P.F.: Pius Felix Princ. Iuv.: Princeps Iuventutis Q.: Quintus Ser.: Servius T.: Titus Ti.: Tiberius Principate Main article: Roman Emperor (Principate) The nature of the imperial office and the Principate was established under Julius Caesar's heir and posthumously adopted son, Caesar Augustus, and his own heirs, the descendants of his wife Livia from her first marriage to a scion of the distinguished Claudian clan. This Julio-Claudian dynasty came to an end when the emperor Nero—a great-great-grandson of Augustus through his daughter and of Livia through her son—was deposed in 68. Nero was followed by a succession of usurpers throughout 69, commonly called the "Year of the Four Emperors". The last of these, Vespasian, established his own Flavian dynasty. Nerva, who replaced the last Flavian emperor, Vespasian's son Domitian, in 96, was elderly and childless, and chose therefore to adopt an heir, Trajan, from outside his family. When Trajan acceded to the purple he chose to follow his predecessor's example, adopting Hadrian as his own heir, and the practise then became the customary manner of imperial succession for the next century, producing the "Five Good Emperors" and the Empire's period of greatest stability. The last of the Good Emperors, Marcus Aurelius, chose his natural son Commodus as his successor rather than adopting an heir. Commodus's misrule led to his murder on 31 December 192, following which a brief period of instability quickly gave way to Septimius Severus, who established the Severan dynasty which, except for an interruption in 217-218, held the purple until 235. Crisis of the Third Century Main article: Roman Emperor (Crisis of the Third Century) The accession of Maximinus Thrax marks both the close and the opening of an era. It was one of the last attempts by the increasingly impotent Roman Senate to influence the succession. Yet it was the second time that a man had achieved the purple while owing his advancement purely to his military career; both Vespasian and Septimius Severus had come from noble or middle class families, while Thrax was born a commoner. He never visited the city of Rome during his reign, which marks the beginning of a series of "barracks emperors" who came from the army. Between 235 and 285 over a dozen emperors achieved the purple, but only Valerian and Carus managed to secure their own sons' succession to the throne; both dynasties died out within two generations. Dominate Main article: Roman Emperor (Dominate) The accession to the purple on 20 November 284, of Diocletian, the lower-class, Greek-speaking Dalmatian commander of Carus's and Numerian's household cavalry (protectores domestici), marked a major departure from traditional Roman constitutional theory regarding the emperor, who was nominally first among equals; Diocletian introduced oriental despotism into the imperial dignity. Whereas before emperors had worn only a purple toga (toga purpura) and been greeted with deference, Diocletian wore jewelled robes and shoes, and required those who greeted him to kneel (proskynesis) and kiss the hem of his robe (adoratio). In many ways, Diocletian was the first monarchical emperor, and this is symbolised by the fact that the word dominus ("Lord") rapidly replaced princeps as the favoured word for referring to the emperor. Significantly, neither Diocletian nor his co-emperor, Maximian, spent much time in Rome after 286, establishing their imperial capitals at Nicomedia and Mediolanum (modern Milan), respectively. Diocletian established the Tetrarchy, a system by which the Roman Empire was divided into East and West, with each having an Augustus to rule over it and a Caesar to assist him. The Tetrarchy ultimately degenerated into civil war, but the eventual victor, Constantine the Great, restored Diocletian's system of dividing the Empire into East and West. He kept the East for himself and founded his city of Constantinople as its new capital.

The dynasty Constantine established was also soon swallowed up in civil war and court intrigue until it was replaced, briefly, by Julian the Apostate's general Jovian and then, more permanently, by Valentinian I and the dynasty he founded in 364. Though he was a soldier from a low middle class background, Valentinian was not a barracks emperor; he was elevated to the purple by a conclave of senior generals and civil officials. Late empire Main article: Roman Emperor (Late Empire) Theodosius I acceded to the purple in the East in 379 and in the West in 394. He outlawed paganism and made Christianity the Empire's official religion. He was the last emperor to rule over a united empire; the distribution of the East to his son Arcadius and the West to his son Honorius after his death in 395 represented a permanent division. In the West, the office of emperor soon degenerated into being little more than a puppet of a succession of Germanic tribal kings, until finally the Heruli Odoacer simply overthrew the child-emperor Romulus Augustulus in 476, shipped the imperial regalia to the emperor Zeno in Constantinople and assumed the title "King of Italy". Though during his own lifetime Odoacer maintained the legal fiction that he was actually ruling Italy as the viceroy of Zeno, historians mark 476 as the traditional date of the fall of the Roman Empire in the West. Large parts of Italy (Sicily, the south part of the peninsula, Ravenna, Venice etc.), however, remained under actual imperial rule from Constantinople for centuries, with imperial control slipping or becoming nominal only as late as the 11th century. In the East, the Empire continued until the fall of Constantinople to the Ottoman Turks in 1453. Although known as the Byzantine Empire by contemporary historians, the empire was simply known as the Roman Empire to its citizens and neighboring countries. For rulers of Italy after Romulus "Augustulus" and Julius Nepos, see list of barbarian kings. For the Roman Emperors who ruled in the East after The Fall in the West, see List of Byzantine Emperors. For emperors of the HRE in the West , see Holy Roman Emperor. See also Byzantine Emperor Holy Roman Emperor Imperator Interregnum Justitium King of Rome Roman Emperors family tree; also Julio-Claudian family tree and Severan dynasty family tree Roman usurper Lists: List of Imperial Victory Titles List of Roman Emperors List of Roman usurpers Notes ^ a b The Oxford Classical Dictionary, entry 'Imperator', Third Edition, Oxford University Press., 1996. ^ Cassius Dio, 43.44.2. ^ Constantine XI Palaeologus (1449-1453) Fall of Constantinople "Ealo h Polis" Further reading Scarre, Chris. Chronicle of the Roman Emperors: The Reign-by-Reign Record of the Rulers of Imperial Rome. London: Thames & Hudson, October 1, 1995. ISBN 0-500-05077-5. (hardcover) External links De Imperatoribus Romanis Rulers of Rome "Decadence, Rome and Romania, and the Emperors Who Weren't", by Kelley L. Ross, Ph.D. UNRV.com The Roman Law Library v · d · eWestern and Eastern Roman emperors Principate 27 BC – 235 AD Augustus · Tiberius · Caligula · Claudius · Nero · Galba · Otho · Vitellius · Vespasian · Titus · Domitian · Nerva · Trajan · Hadrian · Antoninus Pius · Marcus Aurelius with Lucius Verus · Commodus · Pertinax · Didius Julianus · Septimius Severus · Caracalla · Geta · Macrinus with Diadumenian · Elagabalus · Alexander Severus Crisis 235–284 Maximinus Thrax · Gordian I and Gordian II · Pupienus and Balbinus · Gordian III · Philip the Arab · Decius with Herennius Etruscus · Hostilian · Trebonianus Gallus with Volusianus · Aemilianus · Valerian · Gallienus with Saloninus · Claudius Gothicus · Quintillus · Aurelian · Tacitus · Florianus · Probus · Carus · Carinus · Numerian Dominate 284–395 Diocletian · Maximian · Constantius Chlorus · Galerius · Severus · Maxentius · Maximinus Daia · Licinius with Valerius Valens and Martinianus · Constantine I · Constantine II · Constans I · Constantius II with Vetranio · Julian the Apostate · Jovian · Valentinian I · Valens · Gratian · Valentinian II · Theodosius I Western Empire 395–480

Honorius with Constantine · Constantius III · Joannes · Valentinian III · Petronius Maximus · Avitus · Majorian · Libius Severus · Anthemius · Olybrius · Glycerius · Julius Nepos · Romulus Augustulus Eastern/ Byzantine Empire 395–1204 Arcadius · Theodosius II · Marcian · Leo I the Thracian · Leo II · Zeno · Basiliscus · Anastasius I · Justin I · Justinian I · Justin II · Tiberius II Constantine · Maurice · Phocas · Heraclius · Constantine III · Heraklonas · Constans II · Constantine IV · Justinian II · Leontios · Tiberios III · Philippikos · Anastasios II · Theodosios III · Leo III the Isaurian · Constantine V · Artabasdos · Leo IV the Khazar · Constantine VI · Irene · Nikephoros I · Staurakios · Michael I Rangabe · Leo V the Armenian · Michael II the Amorian · Theophilos · Michael III · Basil I the Macedonian · Leo VI the Wise · Alexander · Constantine VII Porphyrogennetos · Romanos I Lekapenos · Romanos II · Nikephoros II Phokas · John I Tzimiskes · Basil II · Constantine VIII · Zoe · Romanos III Argyros · Michael IV the Paphlagonian · Michael V Kalaphates · Constantine IX Monomachos · Theodora · Michael VI · Isaac I Komnenos · Constantine X Doukas  · Romanos IV Diogenes · Michael VII Doukas · Nikephoros III Botaneiates · Alexios I Komnenos · John II Komnenos · Manuel I Komnenos · Alexios II Komnenos · Andronikos I Komnenos · Isaac II Angelos · Alexios III Angelos · Alexios IV Angelos · Nikolaos Kanabos · Alexios V Doukas Empire of Nicaea 1204–1261 Constantine Laskaris · Theodore I Laskaris · John III Doukas Vatatzes · Theodore II Laskaris · John IV Laskaris Eastern/ Byzantine Empire 1261–1453 Michael VIII Palaiologos · Andronikos II Palaiologos · Michael IX Palaiologos · Andronikos III Palaiologos · John V Palaiologos · John VI Kantakouzenos · Matthew Kantakouzenos · Andronikos IV Palaiologos · John VII Palaiologos · Andronikos V Palaiologos · Manuel II Palaiologos · John VIII Palaiologos · Constantine XI Palaiologos v · d · eAncient Rome topics Timeline Epochs Foundation · Monarchy · Republic · Empire · (Principate and Dominate) · Decline · Western Empire / Eastern Empire Constitution History · Constitution of the Kingdom / the Republic / the Empire / the Late Empire · Senate · Legislative assemblies (Curiate, Century, Tribal, Plebeian)  · Executive magistrates Government Curia · Forum · Cursus honorum · Collegiality · Emperor · Legatus · Dux · Officium · Praefectus · Vicarius · Vigintisexviri · Lictor · Magister militum · Imperator · Princeps senatus · Pontifex Maximus · Augustus · Caesar · Tetrarch · Optimates · Populares · Province Magistrates Ordinary Tribune · Quaestor · Aedile · Praetor · Consul · Censor · Promagistrate · Governor Extraordinary Dictator · Magister Equitum · Decemviri · Consular Tribune · Triumvir · Rex · Interrex Law Twelve Tables · Roman citizenship · Auctoritas · Imperium · Status · Litigation Society Social class · Patricians · Plebs · Conflict of the Orders · Secessio plebis · Equestrian order · Gens · Tribes · Naming conventions · Women · Marriage · Slavery Military Borders · Establishment · Structure · Campaigns · Technology · Political control · Frontiers and fortifications (Castra) · Strategy · Engineering · Army (Legion • Infantry tactics • Personal equipment • Siege engines) · Navy (Fleet) · Auxiliaries · Decorations and punishments · Hippika gymnasia Culture Theatre · Cuisine · Education · School · Literature · Art · Music · Architecture · Religion (Funeral • Persecution • Imperial cult) · Mythology · Hairstyle · Public Baths (Thermae)  · Forum · SPQR · Clothing · Chronology (Ab urbe condita · Roman calendar (Julian) · Festivals) · Circus · Wine · Prostitution · Deforestation · Romanization · Cosmetics Technology Numerals · Arithmetic · Abacus · Civil engineering · Military engineering · Military technology · Roads  · Bridges  · Aqueducts  · Metallurgy  · Concrete · Sanitation Roman economy Economy · Agriculture · Commerce · Finance · Currency · Republican currency  · Imperial currency Language (Latin) History · Romance languages (Versions) Old · Classical · Vulgar · Late · Medieval · Renaissance · New · Recent · Ecclesiastical Writers Apuleius · Catullus · Cicero · Curtius Rufus · Horace  · Julius Caesar · Juvenal · Livy · Lucretius · Ovid · Petronius · Plautus  · Pliny the Elder · Pliny the Younger · Propertius · Sallust · Seneca · Suetonius · Tacitus · Virgil · Vitruvius Lists Topics · Wars · Battles · Generals · Legions · Emperors · Geographers · Institutions · Laws · Consuls · Distinguished women Portal