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The Roman Empire


  • The Roman Empire began in 27 BCE when Augustus became the sole ruler of Rome.
  • Augustus and his successors tried to maintain the imagery and language of the Roman Republic to justify and preserve their personal power.
  • Beginning with Augustus, emperors built far more monumental structures, which transformed the city of Rome.

Augustus and the empire

Statue of Augustus from Prima Porta.
Statue of Augustus from Prima Porta. Image credit: Wikimedia, Till Niermann, CC BY-SA 3.0
The Roman Republic became the Roman Empire in 27 BCE when Julius Caesar’s adopted son, best known as Augustus, became the ruler of Rome. Augustus established an autocratic form of government, where he was the sole ruler and made all important decisions. Although we refer to him as Rome’s first emperor, Augustus never took the title of king or emperor, nor did his successors; they preferred to call themselves princeps, first citizen, or primus inter pares, first among peers. This choice of title maintained the appearance of limited power that had been so important under the Republic.
Many of the reforms enacted by Augustus and his successors had a deep and lasting impact on the internal political and economic structures of Rome.
Pax Romana—literally “Roman peace”—is a term often given to the period between 27 BCE and 180 CE during which Roman rule was relatively stable and war less frequent. There were conflicts, such as provincial revolts and wars along the frontier—see the map below showing the extent of Roman control—but Rome experienced nothing like the civil wars that dominated much of the first century BCE. The emperors and the Senate took over most elections and simply chose who they wanted for office, so there were fewer elected political offices to fight over.
Augustus—who, it should be pointed out, came to power through victory in a civil war—ended a string of damaging internal conflicts. Internal stability had positive effects on foreign relations. Because the political and social structures of the empire that Augustus established remained largely unchanged for several centuries, Rome was able to establish regular trade with India and China, further increasing its material wealth through more peaceful means.
Why did Augustus use the title “princeps” and not emperor?
What factors might have made the Roman Empire more stable than the Roman Republic?

Imperial institutions

Augustus and his successors worked hard to maintain much of the image of the Republic while, in practice, they exercised something close to absolute power. Under the Republic, power was shared among many officeholders and limited to short terms. Augustus altered this system by taking many of the offices and their powers for himself while maintaining the idea that these were still separate offices that could, at least in theory, be transferred to someone else. For example, he was the Pontifex Maximus (high priest) and also the censor (overseer of censuses for purposes of taxation) but he never got rid of the offices themselves.
A major component of Augustus’s new power was his control over the military. Under the Republic, the elected consuls served as military commanders during their one-year terms. This occasionally changed in practice, especially during the civil wars of the first century BCE, but the general idea that a military command was always temporary was important to the Romans. So, rather than claiming military power outright, Augustus took control as the stand-in governor of the most dangerous Roman provinces, where the majority of the Roman legions were stationed. This was a clever move because it gave Augustus control of the army while at the same time making it appear that he was doing a favor to the people of Rome.
A map of the Roman Empire at its greatest extent.
Roman Empire at its greatest extent. Client states shown in pink. Image credit: Wikimedia, Tataryn, CC BY-SA 3.0
What difficulties might an emperor have had trying to manage the government of such a large expanse of territory?


Under the empire, Roman currency was not just an economic tool; it was a political tool, as well. Julius Caesar, Augustus’s adopted father, had been the first Roman to put his own portrait on coins, and Augustus continued this practice. Prior to Caesar, only dead Romans or gods were shown on coins. Placing the current emperor’s portrait on coins reinforced the connection between economic power and the emperor, and also helped to shape the popular image of the emperor among the Roman people. Emperors would also use imagery on coins to popularize other family members, political allies, and especially their chosen heirs.
Roman coins depicting the emperor wearing a laurel wreath, which was a symbol of honor and victory; the phrase “DIVVS IVLIV(S)” implies association with the gods.
Roman coins depicting the emperor wearing a laurel wreath, which was a symbol of honor and victory; the phrase “DIVVS IVLIV(S)” implies association with the gods. Image credit: Wikimedia, Classical Numismatic Group, Inc., CC BY-SA 3.0
In a time without photography, newspapers, or television, why might Roman emperors have used currency to spread certain messages about themselves?


Much of the technology used by the Romans remained relatively similar between the Republic and the Empire. However, Augustus altered the systems for overseeing public works, including roads, aqueducts, and sewers. He made permanent the positions of those who oversaw the construction and maintenance of these projects, which helped improve accountability. It also provided a way for the emperor to reward his supporters with important and secure jobs.

Monumental building

Augustus both directly commissioned and indirectly encouraged the construction of multiple temples, a new forum, bathhouses, and theatres. He also erected a monumental arch and the famous Ara Pacis, altar of Augustan peace. These projects helped to solidify Augustus’s power and also served the more concrete purposes of beautifying the city and reducing fire hazards (stone buildings were less susceptible to fires, which had been a frequent source of property damage throughout Roman history).
Like many important and affluent Romans before him, Augustus lived in a typical Roman house on the Palatine Hill in the city of Rome, adding to the illusion that he was just another wealthy citizen. Later emperors took up residence on the Palatine and built an imperial palace on the hill.
The Flavian emperors—Vespasian, Titus, and Domitian—came to power in 69 CE after a brief civil war. They built and restored several temples, a stadium, and an odeum (a building for performing music and plays). The Colosseum was commissioned by Vespasian. Domitian built a larger palace on the Palatine Hill and also constructed many monumental works, including the Arch of Titus, a monument to Titus’s military victory in Jerusalem. Many of these projects were funded by loot taken in the Jewish War, in which Vespasian and his son, Titus, had been the Roman commanders.
Ruins of the imperial palace on the Palatine Hill in Rome, right; the track from the Circus Maximus is visible below the palace, left.
Ruins of the imperial palace on the Palatine Hill in Rome, right; the track from the Circus Maximus is visible below the palace, left. Image credit: Wikimedia, Laurel Lodged, CC0
How might the building of monuments have influenced the Roman people’s view of their emperors?

Foreign policy

The Roman Empire reached its greatest extent in 117 CE, under the emperor Trajan. When Trajan died, much of the territory he conquered in Mesopotamia was quickly lost, but from that point on, Rome’s frontiers became relatively stable.
More stable boundaries led to a new focus on foreign policy. Under the Republic and early empire, the military was often an expansionary force, conquering territory and bringing back loot and enslaved people. In the later Empire, Rome’s legions were stationed along the frontier and served a more defensive role, building fortifications and public works and regulating the movement of people and goods. Much of Roman foreign policy under the empire focused on controlling the people living along its borders and interfering politically, rather than militarily.
How did Rome’s use of the military change during the later imperial period?


Although Augustus fundamentally reorganized the way the Roman state functioned, few ordinary Romans experienced much change in their daily lives. Augustus’s reforms made little difference to social and economic structures. Although his massive building projects and increased foreign trade brought goods, knowledge, and entertainment to the Roman people, these changes can be viewed as the Roman people swapping their old patrician patrons for the emperor. That is, the emperor became the patron of all Romans.

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