Roman Empire
The Roman Empire was the ancient empire centred on the city of Rome, established in 27 BCE when Octavian took the name Augustus, and continuing as the empire of the West until the deposition of Romulus Augustulus in 476 CE; the Eastern Empire survived as the Byzantine Empire until 1453. At its greatest reach under Trajan the empire ran from Britain to Mesopotamia and from the Rhine and Danube to North Africa, defended by a frontier of about 5,000 km. This fact base follows the standard three-part periodization — Republic (509–27 BCE), Principate (27 BCE–284 CE), Dominate (284–476 CE in the West) — and covers government, economy, society, religion, archaeology (Pompeii, Rome, Hadrian’s Wall), and legacy, with every knowledge item carrying a verbatim evidence quote from the cited source.