Roman Empire

Roman Empire

27 BC – 476 AD (traditional dates)[1][2]
395 AD – 480 AD (Western)
395 AD – 1453 AD ( Eastern)

Imperial aquila of Roman Empire
Imperial aquila
The Roman Empire at its greatest extent, 117 AD, the time of Trajan's death (with its vassals in pink)[3]
The Roman Empire at its greatest extent, 117 AD, the time of Trajan's death (with its vassals in pink)[3]
Common languages
Government Semi-elective, functionally absolute monarchy
• 27 BC  – 14 AD
Augustus (first)
• 98–117
• 270–275
• 284–305
• 306–337
Constantine I
• 379–395
Theodosius I[n 3]
• 474–480
Julius Nepos[n 4]
• 475–476
Romulus Augustus
• 527–565
Justinian I
• 610–641
• 780–797
Constantine VI[n 5]
• 976–1025
Basil II
• 1449–1453
Constantine XI[n 6]
Historical eraClassical era to Late Middle Ages
32–30 BC
30–2 BC
•  Constantinople
becomes capital
11 May 330
• Final East-West divide
17 Jan 395
4 Sep 476
• Murder of Emperor Julius Nepos
25 Apr 480
12 Apr 1204
• Reconquest of Constantinople
25 Jul 1261
29 May 1453
• Fall of Trebizond
15 August 1461
25 BC[4]2,750,000 km2 (1,060,000 sq mi)
117 AD[4][5]5,000,000 km2 (1,900,000 sq mi)
390 AD[4]4,400,000 km2 (1,700,000 sq mi)
• 25 BC[6]
Currencysestertius,[n 7] aureus, solidus, nomisma
Preceded by
Succeeded by
Roman Republic
Western Roman Empire
Eastern Roman Empire

The Roman Empire (Latin: Imperium Rōmānum, Classical Latin[ɪmˈpɛrɪ.ũː roːˈmaːnũː]; Koinē Greek: Βασιλεία τῶν Ῥωμαίων, romanized: Basileía tōn Rhōmaíōn) was the post-Republican period of ancient Rome. As a polity it included large territorial holdings around the Mediterranean Sea in Europe, North Africa and West Asia ruled by emperors. From the accession of Caesar Augustus to the military anarchy of the third century, it was a principate with Italy as metropole of the provinces and its city of Rome as sole capital (27 BC – 286 AD). Although fragmented briefly during the military crisis, the empire was forcibly reassembled, then ruled by multiple emperors who shared rule over the Western Roman Empire (based in Milan and later in Ravenna) and over the Eastern Roman Empire (based in Nicomedia and later in Constantinople). Rome remained the nominal capital of both parts until 476 AD, when it sent the imperial insignia to Constantinople (Byzantium - Ancient Greek: Βυζάντιον, Byzántion) following the capture of Ravenna by the barbarians of Odoacer and the subsequent deposition of Romulus Augustus. The fall of the Western Roman Empire to Germanic kings, along with the hellenization of the Eastern Roman Empire into the Byzantine Empire, conventionally marks the end of Ancient Rome and the beginning of the Middle Ages.

The predecessor state of the Roman Empire, the Roman Republic (which had replaced Rome's monarchy in the 6th century BC) became severely destabilized in a series of civil wars and political conflicts. In the mid-1st century BC Julius Caesar was appointed as perpetual dictator and then assassinated in 44 BC. Civil wars and proscriptions continued, culminating in the victory of Octavian, Caesar's adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC. The following year Octavian conquered Ptolemaic Egypt, ending the Hellenistic period that had begun with the conquests of Alexander the Great of Macedon in the 4th century BC. Octavian's power then became unassailable, and in 27 BC the Roman Senate formally granted him overarching power and the new title Augustus, effectively making him the first Roman emperor.

The first two centuries of the Empire saw a period of unprecedented stability and prosperity known as the Pax Romana ("Roman Peace"). Rome reached its greatest territorial expanse during the reign of Trajan (98–117 AD). A period of increasing trouble and decline began with the reign of Commodus (177-192). In the 3rd century the Empire underwent a crisis that threatened its existence, but was reunified under Aurelian (r. 270–275). In an effort to stabilize the Empire, Diocletian set up two different imperial courts in the Greek East and Latin West in 286. Christians rose to positions of power in the 4th century following the Edict of Milan of 313. Shortly after, the Migration Period, involving large invasions by Germanic peoples and by the Huns of Attila, led to the decline of the Western Roman Empire. With the fall of Ravenna to the Germanic Herulians and the deposition of Romulus Augustulus in 476 AD by Odoacer, the Western Roman Empire finally collapsed – the (Eastern Roman) Emperor Zeno formally abolished it in 480 AD. Nonetheless, some states in the territories of the former Western Roman Empire would later claim to have inherited the supreme power of the emperors of Rome, most notably the Holy Roman Empire. The Eastern Roman Empire, identified by modern historians under the name of the Byzantine Empire, survived for another millennium until the Empire's last remains collapsed when Constantinople fell to the Ottoman Turks of Sultan Mehmed II in 1453. (The Ottomans sometimes called their state the "Empire of Rûm" (Ottoman Turkish: دولت علنإه روم‎, lit. 'Exalted State of Rome'). In this sense, it could be argued that a "Roman" Empire survived until the early-20th century.[7])

Due to the Roman Empire's vast extent and long endurance, the institutions and culture of Rome had a profound and lasting influence on the development of language, religion, art, architecture, philosophy, law, and forms of government in the territory it governed, and far beyond. The Latin language of the Romans evolved into the Romance languages of the medieval and modern world, while Medieval Greek became the language of the Eastern Roman Empire. The Empire's adoption of Christianity led to the formation of medieval Christendom. Greek and Roman art had a profound impact on the Italian Renaissance. Rome's architectural tradition served as the basis for Romanesque, Renaissance and Neoclassical architecture, and also had a strong influence on Islamic architecture. The corpus of Roman law has its descendants in many legal systems of the world today, such as the Napoleonic Code, while Rome's republican institutions have left an enduring legacy, influencing the Italian city-states republics of the Medieval period, as well as the early United States and other modern democratic republics.


The Augustus of Prima Porta
(early 1st century AD)

Rome had begun expanding shortly after the founding of the republic in the 6th century BC, though it did not expand outside the Italian peninsula until the 3rd century BC. Then, it was an "empire" long before it had an emperor.[8][9][10][11] The Roman Republic was not a nation-state in the modern sense, but a network of towns left to rule themselves (though with varying degrees of independence from the Roman Senate) and provinces administered by military commanders. It was ruled, not by emperors, but by annually elected magistrates (Roman Consuls above all) in conjunction with the Senate.[12] For various reasons, the 1st century BC was a time of political and military upheaval, which ultimately led to rule by emperors.[9][13][14][15] The consuls' military power rested in the Roman legal concept of imperium, which literally means "command" (though typically in a military sense).[16] Occasionally, successful consuls were given the honorary title imperator (commander), and this is the origin of the word emperor (and empire) since this title (among others) was always bestowed to the early emperors upon their accession.[17]

Rome suffered a long series of internal conflicts, conspiracies and civil wars from the late second century BC onward, while greatly extending its power beyond Italy. This was the period of the Crisis of the Roman Republic. Towards the end of this era, in 44 BC, Julius Caesar was briefly perpetual dictator before being assassinated. The faction of his assassins was driven from Rome and defeated at the Battle of Philippi in 42 BC by an army led by Mark Antony and Caesar's adopted son Octavian. Antony and Octavian's division of the Roman world between themselves did not last and Octavian's forces defeated those of Mark Antony and Cleopatra at the Battle of Actium in 31 BC, ending the Final War of the Roman Republic. In 27 BC the Senate and People of Rome made Octavian princeps ("first citizen") with proconsular imperium, thus beginning the Principate (the first epoch of Roman imperial history, usually dated from 27 BC to 284 AD), and gave him the name "Augustus" ("the venerated"). Though the old constitutional machinery remained in place, Augustus came to predominate it. Although the republic stood in name, contemporaries of Augustus knew it was just a veil and that Augustus had all meaningful authority in Rome.[18] Since his rule ended a century of civil wars and began an unprecedented period of peace and prosperity, he was so loved that he came to hold the power of a monarch de facto if not de jure. During the years of his rule, a new constitutional order emerged (in part organically and in part by design), so that, upon his death, this new constitutional order operated as before when Tiberius was accepted as the new emperor.

The so-called Five Good Emperors (from left to right): Nerva, Trajan, Hadrian, Antoninus Pius and Marcus Aurelius

The 200 years that began with Augustus's rule is traditionally regarded as the Pax Romana ("Roman Peace"). During this period, the cohesion of the empire was furthered by a degree of social stability and economic prosperity that Rome had never before experienced. Uprisings in the provinces were infrequent, but put down "mercilessly and swiftly" when they occurred.[19] The success of Augustus in establishing principles of dynastic succession was limited by his outliving a number of talented potential heirs. The Julio-Claudian dynasty lasted for four more emperors—Tiberius, Caligula, Claudius and Nero—before it yielded in 69 AD to the strife-torn Year of Four Emperors, from which Vespasian emerged as victor. Vespasian became the founder of the brief Flavian dynasty, to be followed by the Nerva–Antonine dynasty which produced the "Five Good Emperors": Nerva, Trajan, Hadrian, Antoninus Pius and the philosophically-inclined Marcus Aurelius.

Fall in the West and survival in the East

The Barbarian Invasions consisted of the movement of (mainly) ancient Germanic peoples into Roman territory. Even though northern invasions took place throughout the life of the Empire, this period officially began in the 4th century and lasted for many centuries, during which the western territory was under the dominion of foreign northern rulers, a notable one being Charlemagne. Historically, this event marked the transition between classical antiquity and the Middle Ages.

In the view of the Greek historian Dio Cassius, a contemporary observer, the accession of the emperor Commodus in 180 AD marked the descent "from a kingdom of gold to one of rust and iron"[20]—a famous comment which has led some historians, notably Edward Gibbon, to take Commodus' reign as the beginning of the decline of the Roman Empire.[21][22]

In 212 AD, during the reign of Caracalla, Roman citizenship was granted to all freeborn inhabitants of the empire. But despite this gesture of universality, the Severan dynasty was tumultuous—an emperor's reign was ended routinely by his murder or execution—and, following its collapse, the Roman Empire was engulfed by the Crisis of the Third Century, a period of invasions, civil strife, economic disorder, and plague.[23] In defining historical epochs, this crisis is sometimes viewed as marking the transition from Classical Antiquity to Late Antiquity. Aurelian (reigned 270–275) brought the empire back from the brink and stabilized it. Diocletian completed the work of fully restoring the empire, but declined the role of princeps and became the first emperor to be addressed regularly as domine, "master" or "lord".[24] Diocletian's reign also brought the empire's most concerted effort against the perceived threat of Christianity, the "Great Persecution".

Diocletian divided the empire into four regions, each ruled by a separate emperor, the Tetrarchy.[25] Confident that he fixed the disorders that were plaguing Rome, he abdicated along with his co-emperor, and the Tetrarchy soon collapsed. Order was eventually restored by Constantine the Great, who became the first emperor to convert to Christianity, and who established Constantinople as the new capital of the eastern empire. During the decades of the Constantinian and Valentinian dynasties, the empire was divided along an east-west axis, with dual power centres in Constantinople and Rome. The reign of Julian, who under the influence of his adviser Mardonius attempted to restore Classical Roman and Hellenistic religion, only briefly interrupted the succession of Christian emperors. Theodosius I, the last emperor to rule over both East and West, died in 395 AD after making Christianity the official religion of the empire.[26]

The Roman Empire by 476

The Western Roman Empire began to disintegrate in the early 5th century as Germanic migrations and invasions overwhelmed the capacity of the Empire to assimilate the migrants and fight off the invaders.[citation needed] The Romans were successful in fighting off all invaders, most famously Attila,[citation needed] though the empire had assimilated so many Germanic peoples of dubious loyalty to Rome that the empire started to dismember itself.[citation needed] Most chronologies place the end of the Western Roman Empire in 476, when Romulus Augustulus was forced to abdicate to the Germanic warlord Odoacer.[27][better source needed] By placing himself under the rule of the Eastern Emperor, rather than naming himself Emperor (as other Germanic chiefs had done after deposing past emperors), Odoacer ended the Western Empire by ending the line of Western emperors.[citation needed] The Eastern Roman Empire, also called Byzantine Empire, continued to exist until Mehmed the Conqueror conquered Constantinople on 29 May 1453.[28]