<Tr> <Td> Western Roman Empire </Td> <Td> </Td> </Tr> <Tr> <Td> Eastern Roman Empire </Td> <Td> </Td> </Tr> <P> The Roman Empire (Latin: Imperium Rōmānum, Classical Latin: (ɪmˈpɛ. ri. ũː roːˈmaː. nũː); Koine and Medieval Greek: Βασιλεία τῶν Ῥωμαίων, tr . Basileia tōn Rhōmaiōn) 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 city of Rome was the largest city in the world c. 100 BC--c . AD 400, with Constantinople (New Rome) becoming the largest around AD 500, and the Empire's populace grew to an estimated 50 to 90 million inhabitants (roughly 20% of the world's population at the time). 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 . 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 . </P> <P> At the accession of Augustus, the Roman Empire covered the entire Italian peninsula, Istria (in modern - day Slovenia and Croatia), the Greek peninsula, western Asia Minor, Syria, Cyrenaica (in modern - day Libya), the area around Carthage (modern - day Tunisia), the Iberian Peninsula (modern - day Spain and Portugal), Transalpine Gaul (modern - day France, Belgium, parts of western Germany, and southern Holland), and the islands of the Mediterranean (the Balearic Islands, Sardinia, Corsica, Sicily, Malta, Crete, the Ionian and Dodecanese Islands, and Cyprus). It also had protectorates over the rest of Asia Minor, Egypt, the Sinai Peninsula and southern Palestine, the eastern part of modern - day Libya, and Numidia (modern - day eastern Algeria). There was conflict along the frontier with Germany, with a massive Roman loss at the Battle of Teutoberg Forest in 9 AD . Although the Romans sent in forces to avenge the loss, they held back from a full - scale invasion of Germany, which Octavian judged would be a disaster . </P>

On what continents was the roman empire located at the height of its expansion