Greek influence from Magna Graecia affected the Romans long before they conquered Greece itself. In the arts, the Romans found much of their inspiration in Greek models. In literature, the Greeks supplied the forms and often much of the spirit. In science and engineering, the Romans accomplished more than the Greeks, as they did in law and government.
Few subjects have been more debated than the reasons for the long decline of the Roman Empire. The celebrated eighteenth-century historian Edward Gibbon blamed Christianity, charging that it destroyed the civic spirit of the Romans by turning their attention to the afterlife and away from their duties to the state. Michael Rostovtzeff, a Russian scholar who wrote in the 1920s and 1930s, attributed the decline in part to the constant pressure by the underprivileged masses to share in the wealth of their rulers, of which there was not enough to go around anyhow.
Commodus (r. 180-192), the true son of Marcus Aurelius, proved to be a tyrant without talent. In the end, his closest advisers murdered him. After two other emperors had been installed and murdered by the Praetorian Guard within a year, Septimus Severus (r. 193-211), a North African who commanded the Roman troops in what is now Hungary, marched his army into Rome and disbanded the guard, replacing it by a new elite body chosen from his own officers.
Augustus’s first four successors are called the Julio-Claudian emperors. Each had been a member of the family of Julius Caesar and Augustus. But now the line had run out. In 68-69, four emperors, each a general supported by his own troops, ruled in rapid succession. The first three died by violence. The fourth was Vespasian, Nero’s commander in Palestine.
Octavian was too shrewd to alienate the people of Rome by formally breaking with the past and proclaiming an empire. He sought to preserve republican forms, but also to remake the government along the lines suggested by Caesar. After sixty years of internal strife, the population welcomed a ruler who promised order.
Caesar became governor of the southern strip of Gaul (modern France), and other adjacent lands. Between 58 and 50 B.C. he defeated the Celtic Gauls, conquering a huge area corresponding to modern France and Belgium. Caesar also crossed the English Channel to punish the Celtic Britons for helping their fellow Celts in Gaul, though he made no effort to conquer Britain permanently.