3. We cannot, therefore, hope to fix any year or event which may properly be taken as the beginning of that long period which followed the downfall of the Roman state in western Europe and which is commonly called the Middle Ages. Beyond the northern and western boundaries of the Roman Empire, which embraced the whole civilized world from the Euphrates to Britain, mysterious peoples moved about whose history before they came into occasional contact with the Romans is practically unknown. These Germans, or barbarians, as the Romans called them, were destined to put an end to the Roman Empire in the West. They had first begun to make trouble about a hundred years before Christ, when a great army of them was defeated by the Roman general, Marius. Julius Cæsar narrates, in polished Latin, familiar to all who have begun the study of that language, how fifty years later he drove back other bands. Five hundred years elapsed, however, between these first encounters and the founding of German kingdoms within the boundaries of the Empire. With their establishment the Roman government in western Europe may be said to have come to an end and the Middle Ages to have begun. Yet it would be a great mistake to suppose that this means that the Roman civilization suddenly disappeared at this time. As we shall see, it had gradually changed during the centuries following the golden age of Augustus, who died A.D. 14. Long before the German conquest, art and literature had begun to decline toward the level that they reached in the Middle Ages. Many of the ideas and conditions which prevailed after the coming of the barbarians were common enough before,--even the ignorance and want of taste which we associate particularly with the Middle Ages. The term _Middle Ages_ is, then, a vague one. It will be used in this volume to mean, roughly speaking, the period of nearly a thousand years that elapsed between the opening of the fifth century, when the disorder of the barbarian invasions was becoming general, and the fourteenth century, when Europe was well on its way to retrieve all that had been lost since the break-up of the Roman Empire. [Sidenote: The 'dark ages.']