Roman Empire

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Joshua J. Mark
published on 22 March 2018
Available in other languages: Chinese, French, Greek, Italian, Portuguese, Russian, Spanish, Turkish
The Provinces of the Roman Empire under Augustus (by Simeon Netchev, CC BY-NC-ND)
The Provinces of the Roman Empire under Augustus
Simeon Netchev (CC BY-NC-ND)

The Roman Empire, at its height (c. 117), was the most extensive political and social structure in western civilization. Building upon the foundation laid by the Roman Republic, the empire became the largest and most powerful political and military entity in the world up to its time and expanded steadily until its fall, in the west, in 476.

By 285, the empire had grown too vast to be ruled from the central government at Rome and so was divided by Emperor Diocletian (r. 284-305) into a Western and an Eastern Empire. The empire began when Augustus Caesar (r. 27 BCE-14 CE) became the first emperor of Rome and ended, in the west, when the last Roman emperor, Romulus Augustulus (r. 475-476), was deposed by the Germanic King Odoacer (r. 476-493). In the east, it continued as the Byzantine Empire until the death of Constantine XI (r. 1449-1453) and the fall of Constantinople to the Ottoman Turks in 1453. The influence of the Roman Empire on western civilization was profound in its lasting contributions to virtually every aspect of western culture.

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The Early Dynasties

Following the Battle of Actium in 31 BCE, Gaius Octavian Thurinus, Julius Caesar's nephew and heir, became the first emperor of Rome and took the name Augustus Caesar. Although Julius Caesar is often regarded as the first emperor of Rome, this is incorrect; he never held the title `Emperor' but, rather, `Dictator', a title the Senate could not help but grant him, as Caesar held supreme military and political power at the time. In contrast, the Senate willingly granted Augustus the title of emperor, lavishing praise and power on him because he had destroyed Rome's enemies and brought much-needed stability.

Augustus: "I found Rome a city of clay but left it a city of marble."

Augustus ruled the empire from 27 BCE until 14 CE when he died. In that time, as he said himself, he "found Rome a city of clay but left it a city of marble." Augustus reformed the laws of the city and, by extension, the empire's, secured Rome's borders, initiated vast building projects (carried out largely by his faithful general Agrippa (l. 63-12 BCE), who built the first Pantheon), and secured the empire a lasting name as one of the greatest, if not the greatest, political and cultural powers in history. The Pax Romana (Roman Peace), also known as the Pax Augusta, which he initiated, was a time of peace and prosperity hitherto unknown and would last over 200 years.

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Following Augustus' death, power passed to his heir, Tiberius (r. 14-37), who continued many of the emperor's policies but lacked the strength of character and vision which so defined Augustus. This trend would continue, more or less steadily, with the emperors who followed: Caligula (r. 37-41), Claudius (r. 41-54), and Nero (r. 54-68). These first five rulers of the empire are referred to as the Julio-Claudian Dynasty for the two family names they descended from (either by birth or through adoption), Julius and Claudius.

Although Caligula has become notorious for his depravity and apparent insanity, his early rule was commendable as was that of his successor, Claudius, who expanded Rome's power and territory in Britain; less so was that of Nero. Caligula and Claudius were both assassinated in office (Caligula by his Praetorian Guard and Claudius, apparently, by his wife). Nero's suicide ended the Julio-Claudian Dynasty and initiated the period of social unrest known as The Year of the Four Emperors.

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These four rulers were Galba, Otho, Vitellius, and Vespasian. Following Nero's suicide in 68 , Galba assumed rule (69) and almost instantly proved unfit for the responsibility. He was assassinated by the Praetorian Guard. Otho succeeded him swiftly on the very day of his death, and ancient records indicate he was expected to make a good emperor. General Vitellius, however, sought power for himself and so initiated the brief civil war which ended in Otho's suicide and Vitellius' ascent to the throne.

Vitellius proved no more fit to rule than Galba had been, as he almost instantly engaged in luxurious entertainments and feasts at the expense of his duties. The legions declared for General Vespasian as emperor and marched on Rome. Vitellius was murdered by Vespasian's men, and Vespasian (r. 69-79) took power exactly one year from the day Galba had first ascended to the throne.

Vespasian founded the Flavian Dynasty which was characterized by massive building projects, economic prosperity, and expansion of the empire. Vespasian's reign was prosperous as evidenced by his building projects which included initial construction of the Flavian Amphitheatre (the famous Coliseum of Rome) which his son Titus (r. 79-81) would complete. Titus' early reign saw the eruption of Mount Vesuvius in 79 which buried the cities of Pompeii and Herculaneum.

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Roman Emperor Domitian, Louvre
Roman Emperor Domitian, Louvre
Mary Harrsch (Photographed at the Musée de Louvre) (CC BY-NC-SA)

Ancient sources are universal in their praise for his handling of this disaster as well as the great fire of Rome in 80. Titus died of a fever in 81 and was succeeded by his brother Domitian (r. 81-96). Domitian expanded and secured the boundaries of Rome, repaired the damage to the city caused by the great fire, continued the building projects initiated by his brother, and improved the economy of the empire. Even so, his autocratic methods and policies made him unpopular with the Roman Senate, and he was assassinated in 96.

The Five Good Emperors

Domitian's successor was his advisor Nerva who founded the Nervan-Antonin Dynasty which ruled Rome 96-192. This period is marked by increased prosperity owing to the rulers known as The Five Good Emperors of Rome. Between 96 and 180, five exceptional men ruled in sequence and brought the Roman Empire to its height:

Under their leadership, the Roman Empire grew stronger, more stable, and expanded in size and scope. Lucius Verus and Commodus are the last two of the Nervan-Antonin Dynasty. Verus was co-emperor with Marcus Aurelius until his death in 169 and seems to have been fairly ineffective. Commodus (r. 180-192), Aurelius' son and successor, was one of the most disgraceful emperors Rome ever saw and is universally depicted as indulging himself and his whims at the expense of the empire. He was strangled by his wrestling partner in his bath in 192, ending the Nervan-Antonin Dynasty and raising the prefect Pertinax (who most likely engineered Commodus' assassination) to power.

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Pompeii and Mt. Vesuvius
Pompeii and Mt. Vesuvius
mchen007 (Copyright)

The Severan Dynasty

Pertinax governed for only three months before he was assassinated. He was followed, in rapid succession, by four others in the period known as The Year of the Five Emperors, which culminated in the rise of Septimus Severus to power. Severus (r. 193-211), founded the Severan Dynasty, defeated the Parthians, and expanded the empire. His campaigns in Africa and Britain were extensive and costly and would contribute to Rome's later financial difficulties. He was succeeded by his sons Caracalla and Geta, until Caracalla had his brother murdered.

Roman Beach Attack
Roman Beach Attack
The Creative Assembly (Copyright)

Caracalla ruled until 217, when he was assassinated by his bodyguard. It was under Caracalla's reign that Roman citizenship was expanded to include all free men within the empire. This law was said to have been enacted as a means of raising tax revenue, simply because, after its passage, there were more people the central government could tax. The Severan Dynasty continued, largely under the guidance and manipulation of Julia Maesa (referred to as "empress"), until the assassination of Alexander Severus (r. 222-235) in 235 which plunged the empire into the chaos known as The Crisis of the Third Century (lasting from 235-284).

Two Empires: East & West

This period, also known as The Imperial Crisis, was characterized by constant civil war, as various military leaders fought for control of the empire. The crisis has been further noted by historians for widespread social unrest, economic instability (fostered, in part, by the devaluation of Roman currency by the Severans), and, finally, the dissolution of the empire which broke into three separate regions. The empire was reunited by Aurelian (270-275) whose policies were further developed and improved upon by Diocletian who established the Tetrarchy (the rule of four) to maintain order throughout the empire.

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The Imperial Crisis was characterized by constant civil war, as various military leaders fought for control of the empire.

Even so, the empire was still so vast that Diocletian divided it in half in c. 285 to facilitate more efficient administration by elevating one of his officers, Maximian (r. 286-305) to the position of co-emperor. In so doing, he created the Western Roman Empire and the Eastern Roman Empire (also known as the Byzantine Empire). Since a leading cause of the Imperial Crisis was a lack of clarity in succession, Diocletian decreed that successors must be chosen and approved from the outset of an individual's reign. Two of these successors were the generals Maxentius and Constantine. Diocletian voluntarily retired from rule in 305, and the tetrarchy dissolved as rival regions of the empire vied with each other for dominance. Following Diocletian's death in 311, Maxentius and Constantine plunged the empire again into civil war.

Constantine & Christianity

In 312, Constantine defeated Maxentius at the Battle of the Milvian Bridge and became sole emperor of both the Western and Eastern Empires (ruling from 306-337 but holding supreme power 324-307). Believing that Jesus Christ was responsible for his victory, Constantine initiated a series of laws such as the Edict of Milan (313) which mandated religious tolerance throughout the empire and, specifically, tolerance for the faith which came to known as Christianity.

The Colossus of Constantine
The Colossus of Constantine
Dana Murray (CC BY-NC-SA)

In the same way that earlier Roman emperors had claimed a special relationship with a deity to augment their authority and standing (Caracalla with Serapis, for example, or Diocletian with Jupiter), Constantine chose the figure of Jesus Christ. At the First Council of Nicea (325), he presided over the gathering to codify the faith and decide on important issues such as the divinity of Jesus and which manuscripts would be collected to form the book known today as The Bible. He stabilized the empire, revalued the currency, and reformed the military, as well as founding the city he called New Rome on the site of the former city of Byzantium (modern-day Istanbul) which came to be known as Constantinople.

He is known as Constantine the Great owing to later Christian writers who saw him as a mighty champion of their faith but, as has been noted by many historians, the honorific could as easily be attributed to his religious, cultural, and political reforms, as well as his skill in battle and his large-scale building projects. After his death, his sons inherited the empire and, fairly quickly, embarked on a series of conflicts with each other which threatened to undo all that Constantine had accomplished.

His three sons, Constantine II, Constantius II, and Constans divided the Roman Empire between them but soon fell to fighting over which of them deserved more. In these conflicts, Constantine II and Constans were killed. Constantius II died later after naming his cousin Julian his successor and heir. Emperor Julian ruled for only two years (361-363) and, in that time, tried to return Rome to her former glory through a series of reforms aimed at increasing efficiency in government.

As a Neo-Platonic philosopher, Julian rejected Christianity and blamed the faith, and Constantine's advocacy for it, for the decline of the empire. While officially proclaiming a policy of religious tolerance, Julian systematically removed Christians from influential government positions, banned the teaching and spread of the religion, and barred Christians from military service. His death, while on campaign against the Persians, ended the dynasty Constantine had begun. He was the last pagan emperor of Rome and came to be known as `Julian the Apostate' for his opposition to Christianity.

Byzantine Empire c. 460 CE
Byzantine Empire c. 460 CE
Tataryn77 (CC BY-SA)

After the brief rule of Jovian, who re-established Christianity as the dominant faith of the empire and repealed Julian's various edicts, the responsibility of emperor fell to Theodosius I. Theodosius I (r. 379-395) took Constantine's and Jovian's religious reforms to their natural ends, outlawed pagan worship throughout the empire, closed the schools and universities, and converted pagan temples into Christian churches after proclaiming Christianity Rome's state religion in 380.

The unity of social duties & religious belief which paganism provided was severed by the institution of Christianity.

It was during this time that Plato's famous Academy was closed by Theodosius' decree. Many of his reforms were unpopular with both the Roman aristocracy and the common people who held to the traditional values of pagan practice. The unity of social duties and religious belief which paganism provided was severed by the institution of a religion which removed the gods from the earth and human society and proclaimed only one God who ruled from the heavens.

This new god, unlike the gods of old, had no special interest in Rome - he was the god of all people - and this distanced the religion of Rome from the state of Rome. Previously, Roman religious belief was state-sponsored and the rituals and festivals went to enhancing the status of the government. Theodosius I devoted so much effort to promoting Christianity that he seems to have neglected other duties as emperor and would be the last to rule both Eastern and Western Empires.

The Fall of the Western Roman Empire, c. 480 CE
The Fall of the Western Roman Empire, c. 480 CE
Simeon Netchev (CC BY-NC-ND)

The Fall of the Roman Empire

From 376-382, Rome fought a series of battles against invading Goths known today as the Gothic Wars. At the Battle of Adrianople, 9 August 378, the Roman Emperor Valens (r. 364-378) was defeated, and historians mark this event as pivotal in the decline of the Western Roman Empire. Various theories have been suggested as to the cause of the empire's fall but, even today, there is no universal agreement on what those specific factors were. Edward Gibbon has famously argued in his The History of the Decline and Fall of the Roman Empire that Christianity played a pivotal role, in that the new religion undermined the social mores of the empire which paganism provided.

The theory that Christianity was a root cause in the empire's fall was debated long before Gibbon, however, as the theologian Orosius (l. c. 5th century) argued Christianity's innocence in Rome's decline as early as 418. Orosius claimed it was primarily paganism itself and pagan practices which brought about the fall of Rome. Other contributing factors to Rome's fall include:

  • Political instability due to size of empire
  • The self-interest of the two halves of the empire
  • Invasion of barbarian tribes
  • Government corruption
  • Mercenary armies
  • Over-reliance on slave labor
  • Massive unemployment and inflation

The ungovernable vastness of the empire, even divided in two, made it difficult to manage. The Eastern Empire flourished while the Western Empire struggled and neither gave much thought to helping the other. Eastern and Western Rome saw each other more as competitors than teammates and worked primarily in their own self-interest. The growing strength of the Germanic tribes and their constant incursions into Rome could have been dealt with more effectively if not for government corruption, especially among provincial governors, and fair treatment of the Goths by the Romans overall.

The Roman military, manned largely with barbarian mercenaries who had no ethnic ties to Rome, could no longer safeguard the borders as efficiently as they once had nor could the government as easily collect taxes in the provinces. Further, the debasement of the currency, begun under the Severan Dynasty, had steadily encouraged inflation while widespread slave labor deprived lower-class citizens of jobs and increased unemployment levels. The arrival of the Visigoths in the empire in the third century, fleeing from the invading Huns, and their subsequent rebellions has also been cited as a contributing factor in the decline.

Invasions of the Roman Empire
Invasions of the Roman Empire
MapMaster (CC BY-SA)

The Western Roman Empire officially ended 4 September 476, when Emperor Romulus Augustulus was deposed by the Germanic King Odoacer (though some historians date the end as 480 with the death of Julius Nepos). The Eastern Roman Empire continued on as the Byzantine Empire until 1453, and though known early on as simply "the Roman Empire", it did not much resemble that entity at all. The Western Roman Empire would become re-invented later as The Holy Roman Empire (962-1806), but that construct, also, was far removed from the Roman Empire of antiquity and was an "empire" in name only.

Legacy of the Roman Empire

The inventions and innovations which were generated by the Roman Empire profoundly altered the lives of the ancient people and continue to be used in cultures around the world today. Advancements in the construction of roads and buildings, indoor plumbing, aqueducts, and even fast-drying cement were either invented or improved upon by the Romans.

The calendar used in the West derives from the one created by Julius Caesar, and the names of the days of the week (in the romance languages) and months of the year also come from Rome. Even the practice of returning some purchase one finds one does not want comes from Rome whose laws made it legal for a consumer to bring back some defective or unwanted merchandise to the seller.

Apartment complexes (known as insula), public toilets, locks and keys, newspapers, even socks all were developed by the Romans as were shoes, a postal system (modeled after the Persians), cosmetics, the magnifying glass, and the concept of satire in literature. During the time of the empire, significant developments were also advanced in the fields of medicine, law, religion, government, and warfare.

The Romans were adept at borrowing from, and improving upon, those inventions or concepts they found among the indigenous populace of the regions they conquered. It is therefore difficult to say what is an "original" Roman invention and what is an innovation on a pre-existing concept, technique, or tool. It can safely be said, however, that the Roman Empire left an enduring legacy which continues to affect the way in which people live in the present day.

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About the Author

Joshua J. Mark
Joshua J. Mark is World History Encyclopedia's co-founder and Content Director. He was previously a professor at Marist College (NY) where he taught history, philosophy, literature, and writing. He has traveled extensively and lived in Greece and Germany.


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Questions & Answers

What are the dates of the Roman Empire?

The Roman Empire began in 27 BCE and, in the West, ended in 476 CE; in the East, it ended in 1453 CE.

Who was the first emperor of Rome?

Augustus Caesar was the first emperor of Rome, reigning 27 BCE-14 CE.

Who were the Five Good Emperors of Rome?

The Five Good Emperors of Rome were: Nerva, Trajan, Hadrian, Antoninus Pius, and Marcus Aurelius who reigned between 96-180 CE.

Why did the Roman Empire fall?

The Roman Empire in the West declined and fell in 476 CE for many reasons including: political instability, religious/cultural instability, government corruption, over-reliance on slave labor, mercenary armies, unemployment and inflation, and invasions by barbarian tribes. In the East, the empire fell to the Ottoman Turks in 1453 CE.

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Mark, J. J. (2018, March 22). Roman Empire. World History Encyclopedia. Retrieved from

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Mark, Joshua J.. "Roman Empire." World History Encyclopedia. Last modified March 22, 2018.

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Mark, Joshua J.. "Roman Empire." World History Encyclopedia. World History Encyclopedia, 22 Mar 2018. Web. 22 Jul 2024.