27 BC-AD 476 Roman Empire

After Octavian's defeat of Antony and Cleopatra in 31 BC, many people hoped that the Republic could be restored. However it soon became clear that a new political system was forming. Although, in theory, Augustus (as Octavian became known) was only the first citizen and ruled by consent of the Senate, he was in fact the Empire's supreme authority. As emperor he could pass his powers to the heir he decreed and was a king in all but name.

The Empire enjoyed unparalleled prosperity as the network of cities boomed, and goods, people and ideas moved freely by land and sea. By the time of the emperor Trajan (AD 98-117) the Roman Empire encompassed the whole of the Mediterranean, Britain, much of northern and central Europe and the Near East.

In the 3rd century the Empire was threatened by economic crisis, weak and short-lived emperors and usurpers, and barbarian incursions. Relative stability was re-established in the 4th century, through the emperor Diocletian's division of the Empire into eastern and western halves. Although some later emperors such as Constantine ruled the whole Empire, the division between east and west became more marked as time passed. Financial pressures, urban decline, underpaid troops and consequently overstretched frontiers finally caused the collapse of the Western Empire in the early 5th century. The last western emperor, Romulus Augustus, was deposed in 476.