Roman emperor

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 magistracy.[9] In Roman tradition, the first triumph was that of Romulus, but the first attested recipient of the title imperator in a triumphal context is Aemilius Paulus in 189 BC.[9] 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.[10]

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 the first emperor Augustus) used imperator as a first name (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.

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 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 façade 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");[11] 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".

In 293, following the Crisis of the Third Century which had severely damaged Imperial administration, Emperor Diocletian enacted sweeping reforms that washed away many of the vestiges and façades of republicanism which had characterized the Augustan order in favor of a more frank autocracy. As a result, historians distinguish the Augustan period as the principate and the period from Diocletian to the 7th-century reforms of Emperor Heraclius as the dominate (from the Latin for "lord".)

Reaching back to the oldest traditions of job-sharing in the republic, however, Diocletian established at the top of this new structure the Tetrarchy ("rule of four") in an attempt to provide for smoother succession and greater continuity of government. Under the Tetrarchy, Diocletian set in place a system of co-emperors, styled "Augustus", and junior colleagues, styled "Caesar". When a co-emperor retired (as Diocletian and his co-emperor Maximian did in 305) or died, a junior "Caesar" would succeed him and the co-emperors would appoint new Caesars as needed.

The four members of Tetrarchy shared military and administrative challenges by each being assigned specific geographic areas of the empire. From this innovation, often but not consistently repeated over the next 187 years, comes the notion of an east–west partition of the empire that became popular with historians long after the practice had stopped. The two halves of empire, while often run as de facto separate entities day-to-day, were always considered and seen, legally and politically, as separate administrative divisions of a single, insoluble imperium by the Romans of the time.

Roman coins (i.e. the tremissis) of the emperors Romulus Augustulus and Julius Nepos, the last emperors of the Western Roman Empire, although Nepos was a de jure ruler in Dalmatia after the deposition of Romulus Augustulus

When emperor Theodosius I died, his sons Arcadius and Honorius, already proclaimed augusti, succeeded him. Eighty-five years later, following Germanic migrations which had reduced the empire's effective control across Britannia, Gaul and Hispania and a series of military coup d'état which drove Emperor Nepos out of Italy, the idea of dividing the position of emperor was formally abolished by Emperor Zeno (480).

The Roman Empire survived in the east until 1453, but the marginalization of the former heartland of Italy to the empire had a profound cultural impact on the empire and the position of emperor. The Greek-speaking inhabitants were Romaioi (Ῥωμαῖοι), and were still considered Romans by themselves and the populations of Eastern Europe and the Near East. The Ottoman Turks still used the term "Rûm" (Rome) when referring to the Eastern empire.[12] Meanwhile, the Tsardom of Russia proclaimed Moscow as the "Third Rome", regarding Constantinople as the "Second Rome".[13]

However, many rulers in Western Europe began to refer to the political entity as the "Greek Empire", regarding themselves as the "true" successors of Rome.[14] The evolution of the church in the no-longer imperial city of Rome and the church in the now supreme Constantinople began to follow divergent paths, culminating in the schism of 1054 between the Roman Catholic and Eastern Orthodox faiths. The position of emperor was increasingly influenced by Near Eastern concepts of kingship. Starting with Emperor Heraclius, Roman emperors styled themselves "basileus" (the title used by Alexander the Great) from 629 onwards.[15] The later period of the empire is today called the Byzantine Empire as a matter of scholarly convention, although this term is still debated.[16]

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 Tribunicia Potestas, or the powers of the tribune of the plebs without actually holding the office (which would have been impossible, since a tribune was by definition a plebeian, whereas Augustus, although born into a plebeian family, had become a patrician when he was adopted into the gens Julia). This endowed the emperor with inviolability (sacrosanctity) of his person, 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 actual tribune of the plebeians. 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 consuls while in the provinces.

Normally, the powers vested in Augustus would have been split between several people, who would each exercise them with the assistance of a colleague and for a specific period of time. Augustus held them all at once by himself, and with no time limits; even those that nominally had time limits were automatically renewed whenever they lapsed.[27]

The nature of the imperial office and the Principate was established under Julius Caesar's heir and posthumously adopted son, 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 practice 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. A brief period of instability quickly gave way to Septimius Severus, who established the Severan dynasty which, except for an interruption in 217–218 when Macrinus was emperor, held the purple until 235.

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,[28] 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.

The accession on 20 November 284, of Diocletian, the lower-class, Greek-speaking Dalmatian commander of Carus's and Numerian's household cavalry (protectores domestici), marked major innovations in Rome's government and constitutional theory. Diocletian, a traditionalist and religious conservative, attempted to secure efficient, stable government and a peaceful succession with the establishment of the Tetrarchy. The empire was divided into East and West, each ruled by an Augustus assisted by a Caesar as emperor-in-waiting. These divisions were further subdivided into new or reformed provinces, administered by a complex, hierarchic bureaucracy of unprecedented size and scope. Diocletian's own court was based at Nicomedia. His co-Augustus, Maximian, was based at Mediolanum (modern Milan). Their courts were peripatetic, and Imperial progressions through the provinces made much use of the impressive, theatrical adventus, or "Imperial arrival" ceremony, which employed an elaborate choreography of etiquette to emphasise the emperor's elevation above other mortals. Hyperinflation of imperial honours and titles served to distinguish the Augusti from their Caesares, and Diocletian, as senior Augustus, from his colleague Maximian. The senior Augustus in particular was made a separate and unique being, accessible only through those closest to him. The overall unity of the Empire still required the highest investiture of power and status in one man.[29]

The Tetrarchy ultimately degenerated into civil war, but the eventual victor, Constantine the Great, restored Diocletian's division of Empire into East and West. He kept the East for himself and founded his city of Constantinople as its new capital. Constantine's own dynasty 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 a soldier from a low middle-class background, Valentinian was made emperor by a conclave of senior generals and civil officials.

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 Roman 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 Western Roman Empire, 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 became 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 Western Roman Empire. 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.

Imaginary portrait of Constantine XI, the last Roman emperor of the Eastern Roman empire

The line of Roman emperors in the Eastern Roman Empire continued unbroken at Constantinople until the capture of Constantinople in 1204 by the Fourth Crusade. In the wake of this action, four lines of Emperors emerged, each claiming to be the legal successor: the Empire of Thessalonica, evolving from the Despotate of Epirus, which was reduced to impotence when its founder Theodore Komnenos Doukas was defeated, captured and blinded by the Bulgarian Emperor Ivan Asen III;[30] the Latin Empire, which came to an end when the Empire of Nicaea recovered Constantinople in 1261; the Empire of Trebizond, whose importance declined over the 13th century, and whose claims were simply ignored;[31] and the Empire of Nicaea, whose claims based on kinship with the previous emperors, control of the Patriarch of Constantinople, and possession of Constantinople through military prowess, prevailed. The successors of the emperors of Nicaea continued 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"). They had also ceased to use Latin as the language of state after Emperor Heraclius (d. 641 AD). Historians have customarily treated the state of these later Eastern emperors under the name "Byzantine Empire". It is important to note, however, that the adjective Byzantine, although historically used by Eastern Roman authors in a metonymic sense, was never an official term.

Constantine XI Palaiologos was the last reigning Roman emperor. A member of the Palaiologos dynasty, he ruled the remnant of the Eastern Roman Empire from 1449 until his death in 1453 defending its capital Constantinople.

He was born in Mystra[32] 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 to 1440.

Before the beginning of the siege, Mehmed the Conqueror made an offer to Constantine XI.[33] 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 line came to an end, almost 1500 years after Augustus.

Charles V was the last emperor of the Holy Roman Empire to receive a papal coronation

The concept of the Roman Empire was renewed in the West with the coronation of the king of the Franks, Charlemagne (Charles the Great), as Roman emperor by the Pope on Christmas Day, 800. This coronation had its roots in the decline of influence of the Pope in the affairs of the Byzantine Empire at the same time the Byzantine Empire declined in influence over politics in the West. The Pope saw no advantage to be derived from working with the Byzantine Empire, but as George Ostrogorsky points out, "an alliance with the famous conqueror of the Lombards, on the other hand ... promised much".[34]

The immediate response of the Eastern Roman emperor was not welcoming. "At that time it was axiomatic that there could be only one Empire as there could be only one church", writes Ostrogorsky. "The coronation of Charles the Great violated all traditional ideas and struck a hard blow at Byzantine interests, for hitherto Byzantium, the new Rome, had unquestionably been regarded as the sole Empire which had taken over the inheritance of the old Roman imperium. Conscious of its imperial rights, Byzantium could only consider the elevation of Charles the Great to be an act of usurpation."[35]

Nikephoros I chose to ignore Charlemagne's claim to the imperial title, clearly recognizing the implications of this act. According to Ostrogorsky, "he even went so far as to refuse the Patriarch Nicephorus permission to dispatch the customary synodica to the Pope."[36] Meanwhile, Charlemagne's power steadily increased: he subdued Istria and several Dalmatian cities during the reign of Irene, and his son Pepin brought Venice under Western hegemony, despite a successful counter-attack by the Byzantine fleet. Unable to counter this encroachment on Byzantine territory, Nikephoros's successor Michael I Rangabe capitulated; in return for the restoration of the captured territories, Michael sent Byzantine delegates to Aachen in 812 who recognized Charlemagne as Basileus.[37] Michael did not recognize him as Basileus of the Romans, however, which was a title that he reserved for himself.[38]

This line of Roman emperors was actually generally Germanic rather than Roman. 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 Catholics 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 last man to be crowned by the pope (although in Bologna, not Rome) was Charles V. All his successors bore only a title of "Elected Roman Emperor".

This line of Emperors 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, the Habsburg Emperors of Austria, and the Hohenzollern heads of the German Reich, this marked the end of the Holy Roman Empire.

Mehmed II

Under Sultan Mehmed II, the Ottoman Empire conquered Constantinople in 1453, an event generally regarded to have marked the definitive end of the Roman Empire,[39] as well as the final and decisive step in the Ottoman conquest of the former empire's core lands and subjects.[40][41][42]

After the conquest of Constantinople in 1453, the sultans of the Ottoman Empire laid claim to be the legitimate Roman emperors, in succession to the Byzantine emperors who had previously ruled from Constantinople.[43] Mehmed had great interest in Roman and classical Greek history, a topic he had been taught on extensively by court teachers in his youth. He emulated himself on Julius Caesar and Alexander the Great, at one point visited the city of Troy to see the graves of the mythological Greek heroes Achilles and Ajax, and kept a copy of the Iliad in his personal library.[44]

Based on the concept of right of conquest, the sultans at times assumed the styles kayser-i Rûm[45][46][47][48] ("Caesar of Rome", one of the titles applied to the Byzantine emperors in earlier Ottoman writings) and basileus (the ruling title of the Byzantine emperors). The assumption of the heritage of the Roman Empire also led the Ottoman sultans to claim to be universal monarchs, the rightful rulers of the entire world.

The early sultans after the conquest of Constantinople—Mehmed II, Bayezid II, Selim I and Suleiman I—staunchly maintained that they were Roman emperors and went to great lengths to legitimize themselves as such. Greek aristocrats, i.e. former Byzantine nobility, were often promoted to senior administrative positions and Constantinople was maintained as the capital, rebuilt and considerably expanded under Ottoman rule. The administration, architecture and court ceremonies of the early post-1453 Ottoman Empire were heavily influenced by the former Byzantine Empire. The Ottoman sultan also used their claim to be Roman emperors to justify campaigns of conquest against Western Europe. Both Mehmed II and Suleiman I dreamt of conquering Italy, which they believed was rightfully theirs due to once having been the Roman heartland. Although the claim to Roman imperial succession never formally stopped and titles such as kayser-i Rûm and basileus were never formally abandoned, the claim gradually faded away and ceased to be stressed by the sultans.

• List of Roman emperors
• List of Byzantine emperors
• List of Holy Roman emperors
• List of Ottoman sultans
• List of Italian monarchs
• List of Roman usurpers
• List of condemned Roman emperors
• List of Imperial Roman victory titles