The Roman Empire emerged after the assassination of Caesar in 44 BC. After Caesar's, death, there were years of civil war. Finally, in 27 BC, Augustus became Caesar's successor and the emperor of Rome.
Augustus (63 BC–14 AD) enjoyed a long and prosperous reign. His rule marked the beginning of the Pax Romana—two hundred years of peace. He was a capable organizer and reformer, but his power was absolute. He suffered only one setback as emperor: the Germans wiped out a Roman force at Teutoburg Forest in 9 AD.
One characteristic of the Roman Empire was its vastness. It stretched from Scotland to the Arabian desert and from Morocco to the Black Sea. The Mediterranean Sea was a de facto Roman lake. Roman territory was so extensive that Augustus decided not to enlarge it any further.
The huge empire was held together by a first-rate system of roads. A postal service was run by the military. Industry and commerce thrived, and goods were efficiently carried by ship. Literature and art—usually inspired by Greece—flourished.
After the Pax Romana, the empire began to decline. The rise of Christianity vexed Rome. Some of the subsequent Roman emperors, such as Commodus, were unusually cruel and inept. Barbarian tribes pressed against the Roman frontiers.
Rome finally collapsed in 476.