The Roman Empire

The Roman Empire was the post-Roman Republic period of the ancient Roman civilization, characterized by government headed by emperors and large territorial holdings around the Mediterranean Sea in Europe, Africa and Asia. The 500-year-old republic which preceded it was severely destabilized in a series of civil wars and political conflict, during which Julius Caesar was appointed as perpetual dictator and then assassinated in 44 BC.

The construction of Coliseum started in 70 CE

Civil wars and executions continued, culminating in the victory of Octavian, Caesar's adopted son, over Mark Antony and Cleopatra at the Battle of Actium in 31 BC and the annexation of Egypt. Octavian's power was then unassailable and in 27 BC the Roman Senate formally granted him overarching power and the new title Augustus, effectively marking the end of the Roman Republic.

Wall painting (1st century AD) from Pompeii depicting a multigenerational banquet

The imperial period of Rome lasted approximately 1,500 years compared to the 500 years of the Republican era. The first two centuries of the empire's existence were a period of unprecedented political stability and prosperity known as the Pax Romana, or "Roman Peace".


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

The suicide of emperor Nero, in 68, was followed by a brief period of civil war. Between June of 68 and December of 69, Rome witnessed the successive rise and fall of Galba, Otho, and Vitellius until the final accession of Vespasian, first of the Imperial Flavian dynasty, in July 69. The social, military and political upheavals of the period had Empire-wide repercussions, which included the outbreak of the Batavian rebellion.

Nero

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.

Marcus Aurelius

In 212, 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(193 CE - 235 CE) was tumultuous — an emperor's reign was ended routinely by his murder or execution. It was the last lineage of the Principate founded by Augustus.

Caracalla

Following the collapse  Severan dynasty, the Roman Empire was engulfed by the Crisis of the Third Century, a period of invasions, civil strife, economic disorder, and plague. In defining historical epochs, this crisis is sometimes viewed as marking the transition from Classical Antiquity to Late Antiquity.

Crises of the Third Century in 235, initiating a fifty-year period in which there were at least thirty claimants to the title of Emperor, mostly prominent Roman army generals, who assumed imperial power over all or part of the Empire. Twenty-six men were officially accepted by the Roman Senate as emperor during this period, and thus became legitimate emperors.

Diocletian's reign(crowned 284 CE) brought the empire's most concerted effort against the perceived threat of Christianity, the "Great Persecution". He divided the empire into four regions, each ruled by a separate emperor, the Tetrarchy. Confident that he fixed the disorders that were plaguing Rome, he abdicated along with his co-emperor, and the Tetrarchy soon collapsed. The state of absolute monarchy that began with Diocletian endured until the fall of the Eastern Roman Empire in 1453.

Diocletian

Order was eventually restored by Constantine the Great, who became the first emperor(crowned 306 CE) 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.

Bronze statue of Constantine I in York, England, near the spot where he was proclaimed Augustus in 306.

The reign of Julian, who 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. 

Theodosius I