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— CH. 1 · INTRODUCTION —

Roman emperor

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  • In January 27 BC, a man stood before the Roman Senate and announced he was giving power back to the people. The Senate thanked him, confirmed him as princeps, the first among equals, and awarded him a new honorific: augustus, meaning elevated. That man was Octavian, and the gesture was a performance. He would never give the power back. What followed was over a thousand years of Roman emperors, an office so fluid, so contested, and so deliberately undefined that ancient writers could not even agree on who the first emperor was, or how many there had been in total. How did an institution rooted in the fiction of a republic become the most durable monarchical tradition in Western history? And what happened when it finally ran out of room to survive?

  • Julius Caesar had been pontifex maximus since 64 BC and held the consulship and dictatorship multiple times from 59 BC onward. He was appointed dictator in perpetuity in 44 BC, shortly before his killers, who called themselves the liberatores, cut him down. They declared they were restoring the Republic. Within a short time, Caesar's supporters had dismantled that claim entirely. From the moment Octavian inherited Caesar's name and allies, the question was never whether one man would rule Rome. It was what that rule would be called. No single new title was coined to describe the emperor. Instead, Augustus accumulated Republican offices, pontifex maximus, tribunician power, supreme military command, and made them permanent. The Senate in 27 BC gave him control over nearly all Roman provinces for a tenure of ten years, a limit that was, in practice, automatically renewed. For the first three centuries of emperors, every effort was made to dress this monarchy in republican clothing. Emperors styled themselves leaders of the Republic rather than kings, because the memory of the kings who ruled Rome before the Republic was an object of deep revulsion. Modern historians, using 27 BC as the symbolic start date of the Roman Empire, acknowledge that the Republic had in fact dissolved considerably earlier. Most Romans simply recognized the emperor as whoever ruled the state, with no particular title needed.

  • The only surviving document to describe the emperor's formal powers in direct legal terms is the Lex de imperio Vespasiani, written shortly after Vespasian's accession in December 69 AD. What survives is only the second half of the text. It lists specific grants: Vespasian may make treaties, convene the Senate, endorse candidates, expand the city's sacred boundary, and exercise discretionary power whenever necessary. The document also states, explicitly, that he is not bound by laws, and that any act performed before his formal recognition was retroactively considered legitimate. Nowhere in the text does the word emperor appear. Nowhere is there mention of the tribunician power or the supreme command. Those powers were almost certainly enumerated in the now-lost first half. The most important bases of real power were what jurists called imperium maius, the supreme power of command, and tribunicia potestas, the power of the tribunes, both held by Augustus from 23 BC onward. Tribunician power was renewable each year, coinciding with the regnal year, though regnal years were not officially adopted until the reign of Justinian I. It allowed the emperor to veto any act by any magistrate, propose laws, convoke the Senate, and claim sacrosanctity, making any offence against him a crime of treason. Augustus had received elements of this power since 36 BC, long before its formal grant. The title of censor was not absorbed into the imperial office until Domitian declared himself perpetual censor in 85 AD.

  • Theodor Mommsen, the great 19th-century historian of Rome, observed that there had probably never been a regime in which the notion of legitimacy was as absent as in the Augustan principate. He was right, and the consequences were severe. Formally announcing a successor would have confirmed Augustus as a monarch, so he and his heirs relied instead on adoption, carefully presenting chosen successors as worthy sons rather than designated heirs. Augustus adopted Tiberius; Tiberius was confirmed as princeps after Augustus died in 14 AD and had already held legally equal powers since 4 AD. The office was not truly defined as a singular, transferable position until Caligula's accession, when all of Tiberius' powers were transferred automatically to him as a single abstract entity. Vespasian was the first emperor to openly name his sons Titus and Domitian as his sole heirs. After Domitian's murder in 96 AD, the Senate named Nerva, one of their own members, as the new emperor, the only time since Nerva that the Senate took that initiative before collapsing again. Between Commodus's murder in 192 and the 5th century, scarcely a decade passed without succession conflict and civil war. Who counted as a legitimate emperor and who was a usurper was, in practice, decided retrospectively. Septimius Severus declared himself the adoptive son of the long-dead Marcus Aurelius to assert dynastic credibility, and named his son Caracalla accordingly. The Lex de imperio Vespasiani states outright that legitimacy was, in Mommsen's phrase, a post factum phenomenon. The year 193 has traditionally been called the Year of the Five Emperors, but modern scholarship now classifies Clodius Albinus and Pescennius Niger as usurpers because the Senate did not recognize them, even as Maxentius, who held Rome for years with the Senate's recognition, is sometimes still called a usurper because the Tetrarchs did not acknowledge him.

  • Severus Alexander, the last member of his line, was murdered in 235 AD, triggering the Crisis of the Third Century, fifty years that nearly destroyed the Roman Empire. During this period even the formality of seeking senatorial confirmation eroded. Maximinus Thrax and Carus never set foot in Rome. Carus's successors did not bother to assume the tribunician power at all. When Diocletian reunited the empire in 285, he looked not to the Republic for a model but to the most ancient Roman tradition: shared rule. He established the Tetrarchy, two senior emperors called augusti and two junior heirs called caesares. When an augustus retired or died, his caesar was to succeed him and appoint a new caesar in turn. Diocletian himself retired in 305, as did his co-emperor Maximian. He justified his rule not by military power but by divine right, declaring himself Jovius, son of Jupiter, and designating Maximian as Herculius, son of Hercules. With this, the republican pretense collapsed entirely. Emperors adopted the diadem crown as the supreme symbol of power. The Senate no longer ratified imperial authority. The emperor became the sole source of law, delivered not to the public but to the praetorian prefects, who had evolved from the emperor's bodyguards into the heads of great administrative districts. The last emperor to use the traditional titles of proconsul and pater patriae was Anastasius I, at the start of the 6th century. The office of consul was not abolished until 892, during the reign of Leo VI.

  • The permanent division of the empire into East and West became fixed on the death of Theodosius I in 395, when he was succeeded simultaneously by his sons Honorius in the West and Arcadius in the East. Legally and politically, Romans continued to regard this as one insoluble state with two administrative branches, not as two separate empires. In practice, the Western court lost control rapidly. By the late 5th century the real power behind Western emperors belonged to Germanic generals such as Aetius and Ricimer. The last Western emperors were known as shadow emperors. In 476, the Heruli commander Odoacer overthrew the child-emperor Romulus Augustulus, made himself king of Italy, and sent the imperial regalia to Zeno in Constantinople. Julius Nepos, whom Romulus had displaced, continued to claim the title from Dalmatia until his murder in 480. The Eastern court recognized Nepos's claim and Odoacer minted coins bearing his name, though Nepos exercised no real authority. With Nepos's death, Zeno became technically the sole emperor of a reunited Roman Empire, though he had no power whatsoever in the former Western territories. Odoacer himself never claimed the imperial dignity. His successor Theodoric the Great governed as rex, yet used the titles of princeps Romanus and dominus noster and even retrieved the regalia that Odoacer had shipped east. The last attempt to restore a Western emperor came during the Siege of Ravenna in 539-540, when the Goths offered Belisarius the throne, an offer he refused.

  • Heraclius in 629, following his victory over the Persians, became the first emperor to officially style himself basileus, the traditional Greek title for monarchs used since the time of Alexander the Great. The title had circulated informally since the beginning of the empire and appeared regularly in unofficial usage by the 3rd century, but did not surface in official documents until the 7th century. Michael I Rangabe was the first emperor to formally use the full title Basileus Romaion, emperor of the Romans, a move that was itself a response to Charlemagne's coronation by Pope Leo III on Christmas Day 800 AD. In crowning Charlemagne, the papacy created a rival lineage of Roman emperors in western Europe that would persist in the Holy Roman Empire until 1806. Eastern emperors never recognized this claim, and the coronations produced what medieval writers called the problem of two emperors. The Eastern line continued unbroken until 1204, when the sack of Constantinople by crusaders created three lines of emperors in exile: those of Nicaea, those of Trebizond, and the short-lived rulers of Thessalonica. The Nicaean emperors recovered Constantinople in 1261. The Empire of Trebizond survived until 1461, though from 1282 its rulers had adopted a modified title acknowledging the Nicaean claim to sole Roman legitimacy. Constantine XI Palaiologos, the last Eastern emperor, died in battle when Constantinople fell to the Ottoman Turks in 1453. Mehmed II then claimed the Roman throne by right of conquest, and Suleyman the Magnificent later integrated kayser-i Rum, Caesar of Rome, into his full imperial title. The word caesar itself traveled further: Kaiser in Germany and Tsar in Bulgaria and Russia both descend from the name of Gaius Julius Caesar.

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Augustus (title)

Common questions

When did the Roman emperor title officially begin?

The title augustus was granted to Octavian by the Roman Senate in January 27 BC, the date most modern historians use as the start of the Roman Empire. Most Romans simply regarded the emperor as whoever held supreme power, with no single formal title defining the office.

Who was the first Roman emperor?

Modern historians regard Augustus (Octavian) as the first Roman emperor. Most ancient Roman writers, including Pliny the Younger, Suetonius, and Appian, considered Julius Caesar the first emperor, while Plutarch, Tacitus, and Cassius Dio agreed with the modern view that Caesar was the last dictator of the Republic.

How did Roman emperors legitimize their power?

Legitimacy depended on control of the Roman army and recognition by the Senate, though in practice it was often determined retrospectively. An emperor's proclamation by troops, distribution of coins and statues, claimed blood or adoptive connections to past emperors, and propaganda were all used to assert legitimacy, by both recognized emperors and usurpers alike.

When did the Western Roman Empire fall and who was the last Western emperor?

Romulus Augustulus was overthrown by Odoacer in 476, the date historians mark as the fall of the Western Roman Empire. Julius Nepos, who had been displaced by Romulus, continued to claim the title from Dalmatia until his murder in 480, and the Eastern court recognized his claim until his death.

What were the main titles used by Roman emperors?

The principal titles were imperator, caesar, augustus, princeps, and, in the Eastern Empire from 629 onward, basileus. The formula Imperator Caesar followed by the full name and Augustus became standard from the reign of Antoninus Pius. In the Eastern Empire the full title eventually became basileus and autokrator of the Romans.

Who was the last Eastern Roman emperor and when did the Eastern Empire fall?

Constantine XI Palaiologos was the last Eastern Roman emperor. He died in battle during the fall of Constantinople to the Ottoman Turks in 1453. The last remnants of the empire, Morea and Trebizond, fell in 1461.

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All sources

91 references cited across the entry

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  2. 2BookAugustus: The Life of Rome's First EmperorAnthony Everitt — Random House Publishing — 9 October 2007
  3. 3Bowman, Champlin, Lintott (1996) p. 76-87Bowman, Champlin, Lintott — 1996
  4. 4Eutropius, Breviarium 7.8 "From that period he held the government as sole ruler for forty-four years, for during the twelve previous years he had held it in conjunction with Antony and Lepidus. Thus
  5. 5Jerome, Chronichon, 184th Olympiad. "2nd ruler of the Romans, Octavianus Caesar Augustus reigned for 56 years and 6 months; from whom the kings (basileus) of the Romans are called Augusti."
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  73. 73Paterculus (II, 80–90), for example, only uses princeps, but the English text translates the word directly as "emperor". Livy (I. 19) calls Augustus imperator once, but he also uses the term when writ
  74. 74Res Gestae I.7, "For ten years in succession I was one of the triumvirs for the re-establishment of the constitution. To the day of writing this June/July AD 14 I have been princeps senatus for forty
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