Roman Empire

The Roman Empire was the post-republican phase of ancient Rome and one of the most influential states in world history.

It began in 27 BCE when Octavian, granted the title Augustus, became the first emperor, ending the civil wars that had destroyed the Republic and inaugurating a long period of relative stability known as the Pax Romana. At its height under Trajan in the early second century CE, the empire encompassed around five million square kilometres and perhaps a fifth of the world's population, stretching from Britain and the Atlantic coast across the Mediterranean to Egypt, the Levant, and Mesopotamia. Rome governed this vast and diverse realm through a sophisticated system of provinces, a professional standing army, an extensive network of roads and cities, a common legal framework, and a shared elite culture blending Roman and Greek traditions. Roman achievements in law, engineering, architecture (such as concrete construction, aqueducts, and monumental public buildings), literature, and administration shaped the subsequent development of European and Mediterranean civilisation. The empire also became the vehicle for the spread of Christianity, which was legalised under Constantine in the fourth century and later made the state religion. From the third century the empire faced mounting crises: civil wars, economic difficulties, plague, and increasing pressure from peoples along its frontiers. It was administratively divided into western and eastern halves, with the east governed from Constantinople. The Western Roman Empire gradually fragmented under the strain of invasions and internal weakness, conventionally ending in 476 CE when the last western emperor was deposed. The eastern half continued for another thousand years as the Byzantine Empire.

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