In the past you rivalled the Achaians and the Macedonians, peoples of your own race, and Philip, their commander, for the hegemony and glory, but now… - Polybius

For what gives my work its peculiar quality, and what is most remarkable in the present age, is this. Fortune has guided almost all the affairs of the world in one direction and has forced them to incline towards one and the same end; a historian should likewise bring before his readers under one synoptical view the operations by which she has accomplished her general purpose.

I observe that while several modern writers deal with particular wars and certain matters connected with them, no one, as far as I am aware, has even attempted to inquire critically when and whence the general and comprehensive scheme of events originated and how it led up to the end. I therefore thought it quite necessary not to leave unnoticed or allow to pass into oblivion this the finest and most beneficent of the performances of Fortune. For though she is ever producing something new and ever playing a part in the lives of men, she has not in a single instance ever accomplished such a work, ever achieved such a triumph, as in our own times. We can no more hope to perceive this from histories dealing with particular events than to get at once a notion of the form of the whole world, its disposition and order, by visiting, each in turn, the most famous cities, or indeed by looking at separate plans of each: a result by no means likely. He indeed who believes that by studying isolated histories he can acquire a fairly just view of history as a whole, is, as it seems to me, much in the case of one, who, after having looked at the dissevered limbs of an animal once alive and beautiful, fancies he has been as good as an eyewitness of the creature itself in all its action and grace.

How striking and grand is the spectacle presented by the period with which I purpose to deal, will be most clearly apparent if we set beside and compare with the Roman dominion the most famous empires of the past, those which have formed the chief theme of historians. Those worthy of being thus set beside it and compared are these. The Persians for a certain period possessed a great rule and dominion, but so often as they ventured to overstep the boundaries of Asia they imperilled not only the security of this empire, but their own existence. The Lacedaemonians, after having for many years disputed the hegemony of Greece, at length attained it but to hold it uncontested for scarce twelve years. The Macedonian rule in Europe extended but from the Adriatic region to the Danube, which would appear a quite insignificant portion of the continent. Subsequently, by overthrowing the Persian empire they became supreme in Asia also. But though their empire was now regarded as the greatest geographically and politically that had ever existed, they left the larger part of the inhabited world as yet outside it. For they never even made a single attempt to dispute possession of Sicily, Sardinia, or Libya, and the most warlike nations of Western Europe were, to speak the simple truth, unknown to them. But the Romans have subjected to their rule not portions, but nearly the whole of the world and possess an empire which is not only immeasurably greater than any which preceded it, but need not fear rivalry in the future. In the course of this work it will become more clearly intelligible by what steps this power was acquired, and it will also be seen how many and how great advantages accrue to the student from the systematic treatment of history.