When Did the Roman Empire Begin? Augustus in 27 BCE
When did the Roman Empire begin? Understand Augustus's settlement in 27 BCE and why 753, 509, 44 and 31 BCE answer different questions.
Last updated October 2026
Contents8
- When did the Roman Empire begin: at a glance
- What happened in 27 BCE?
- Why Rome's founding is a different beginning
- Why 509 BCE belongs to the Republic
- Was Caesar's dictatorship the beginning?
- Why Actium matters, but 27 BCE is usual
- Did the Eastern Roman Empire have a separate start?
- Verdict: When did the Roman Empire begin
The Roman Empire is usually dated from 27 BCE. Octavian then received the title Augustus and reached a deal with the Senate. Rome's traditional founding was in 753 BCE. Metropolitan Museum of Art: The Roman Empire (27 BCE–393 CE) World History Encyclopedia: Ancient Rome
The Republic began in 509 BCE. Both dates mark earlier forms of rule.
The important change was rule by an emperor. Rome had already conquered lands beyond Italy under the Republic. The Eastern Roman Empire overview follows the imperial story through its later eastern survival. World History Encyclopedia: Roman Republic World History Encyclopedia: Byzantine Empire
TL;DR: Use 27 BCE for the start of the empire under Augustus. Use 753 BCE for Rome's traditional founding and 509 BCE for the conventional start of the Republic. Caesar's dictatorship and Octavian's victory at Actium helped produce imperial rule. But neither is the usual formal starting date.
When did the Roman Empire begin: at a glance
The entries follow World History Encyclopedia, World History Encyclopedia: Augustus, Metropolitan Museum of Art: The Roman Empire (27 BCE–393 CE).
| Date | Event | What it starts or changes | Status |
|---|---|---|---|
| 753 BCE | Traditional founding by Romulus | Rome's legendary city history | Disputed |
| 509 BCE | Conventional overthrow of the monarchy | Roman Republic | Reviewed |
| 44 BCE | Caesar's dictatorship for life and murder | A crisis in the Republic, before Augustus | Reviewed |
| 31 BCE | Octavian defeated Antony and Cleopatra at Actium | A decisive step toward sole rule | Reviewed |
| 27 BCE | Octavian became Augustus in the Senate settlement | Usual beginning of the Roman Empire | Reviewed |
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What happened in 27 BCE?
Octavian had won the civil wars and held the military strength needed to keep power. He could not safely act as though those wars had never happened. Nor could he ignore Roman hostility to the title of king. His settlement presented his power through forms that the Senate could accept. World History Encyclopedia
He received the name Augustus and control over key provinces. Republican offices and the Senate remained. The old offices made the new order look familiar. Yet one man now held the key power. Metropolitan Museum of Art: The Roman Empire (27 BCE–393 CE)
This early imperial system is called the Principate. The term is linked to the idea of the ruler as the leading citizen. Augustus joined personal command with old public offices. He did not announce a return to kingship.
The settlement was part of a process. Augustus continued to adjust his powers after it. Using one starting date gives a clear marker. It does not mean that every rule of government was created in one Senate meeting.
See who is the first Roman emperor for Augustus's place in the ruler list. His position explains why a history of emperors normally begins with him.
Why Rome's founding is a different beginning
The story of Romulus and Remus places Rome's founding in 753 BCE. Ancient accounts tell of the brothers, the she-wolf and a quarrel over the new city. The tradition became a powerful part of Roman identity. It is not a contemporary record that proves an exact founding day. World History Encyclopedia
Rome developed from settlements into a city. Its early royal period and the later Republic came before Augustus. Calling the founding the start of the empire would merge those different forms of rule.
The difference is simple: a city can exist long before it becomes the capital of a large empire. Its people can also remember an origin story without having complete records of the event. A founding date and a government date answer separate questions.
The Roman Empire timeline begins with the traditional founding so readers can see the whole sequence. The empire's starting date appears later in that sequence.
Why 509 BCE belongs to the Republic
The conventional date for the monarchy's end is 509 BCE. Roman tradition links it to the expulsion of Tarquin the Proud. The new Republic placed power in public offices, including consuls, rather than a royal household. World History Encyclopedia
Its early development is less clear than the neat traditional date suggests. The evidence for Rome's earliest government is incomplete, and later writers supplied much of the story. The date remains a standard marker in a broad timeline. World History Encyclopedia
Under the Republic, Rome conquered much of the Mediterranean. It ruled provinces and demanded resources from subject peoples. That makes it possible to speak of a Republican empire in a land sense.
In the usual sequence of Kingdom, Republic and Empire, however, the word Empire names the era of emperors. Keeping those meanings apart resolves much of the apparent disagreement about when it began.
Was Caesar's dictatorship the beginning?
Julius Caesar concentrated power in his own hands and became dictator for life in 44 BCE. His power helped break the Republic's old balance. He was killed that same year, and civil war continued. World History Encyclopedia World History Encyclopedia
Caesar did not hold the later position created under Augustus. Dictator was a Roman office with its own history. A dictator could hold great power. That alone did not make him an emperor.
His importance is still central. Augustus was Caesar's heir, took his name and used the family link in his rise. The later imperial title Caesar carried that link into the new system.
The was Julius Caesar an emperor page explains the title problem. It separates Caesar's personal power from the later office associated with his name.
Why Actium matters, but 27 BCE is usual
At Actium in 31 BCE, Octavian defeated the forces of Antony and Cleopatra. The victory removed the main rival coalition and opened the way to sole rule. It was the military turning point behind the later settlement. World History Encyclopedia
Military victory and public settlement are different events. Actium explains how Octavian gained the position from which he could shape the government. The settlement explains the form in which that power was presented and kept.
Thus a narrative may begin the imperial story with Actium. A reference answer usually uses 27 BCE. The events are linked. One won the power; the other marks the formal starting point.
The sequence is easier to remember as civil war, decisive victory, then settlement. Augustus's power developed through those stages. It was not simply the result of a new title.
Did the Eastern Roman Empire have a separate start?
The eastern empire continued the Roman state. Constantine's new capital and later divisions of rule are useful markers in its development. But they do not replace Augustus as the starting point of the whole imperial era. World History Encyclopedia
Historians choose different boundaries when they want to study the eastern state on its own. A date for a new capital answers a different question from a date for the first emperor. That is why the same broad history can have several valid period labels.
For the other end of the span, see when did the Roman Empire fall. For duration and the BCE–CE arithmetic, see how long did the Roman Empire last.
Verdict: When did the Roman Empire begin
The standard answer is 27 BCE, with Augustus's Senate settlement. Rome's founding, the Republic's beginning, Caesar's dictatorship and Actium belong to the chain of events that preceded it. Name the event beside the date, and the different answers become much easier to compare.
Sources checked for this page
- Metropolitan Museum of Art: The Roman Empire (27 BCE–393 CE)
- Ancient Rome - World History Encyclopedia
- Roman Republic - World History Encyclopedia
- Byzantine Empire - World History Encyclopedia
- Augustus - World History Encyclopedia
Questions people also ask
What year did the Roman Empire begin?
The usual year is 27 BCE, when Octavian received the title Augustus and reached his settlement with the Senate.
Did the Roman Empire begin in 753 BCE?
No. That is the traditional founding date of Rome, before its Republic and imperial government.
Did Julius Caesar start the Roman Empire?
Caesar's dictatorship helped end the Republic's old political balance, but Augustus is normally counted as the first emperor.
Why is 31 BCE sometimes mentioned?
Octavian's victory at Actium removed Antony and Cleopatra as rivals and prepared the way for his lasting sole rule.
What was the Principate?
It was the early imperial form of government, which kept Republican institutions while concentrating lasting authority in the emperor.
Was the Roman Republic already an empire?
It ruled conquered provinces, so it had an empire in the territorial sense. The era called the Roman Empire usually means the later government under emperors.