And do not imagine that what we are fighting for is simply the question of freedom or slavery: there is also involved the loss of our empire and the dangers arising from the hatred which we have incurred in administering it. Nor is it any longer possible for you to give up this empire, though there may be some people who in a mood of sudden panic and in a spirit of political apathy actually think that this would be a fine and noble thing to do. Your empire is now like a tyranny: it may have been wrong to take it; it is certainly dangerous to let it go.

(Pericles:) And do not imagine that you are fighting about a simple issue, freedom or slavery; you have an empire to lose, and there is the danger to which the hatred of your imperial rule has exposed you.

Neither can you resign your power, if, at this crisis, any timorous or inactive spirit is for thus playing the honest man. For by this time your empire has become a tyranny which in the opinion of mankind may have been unjustly gained, but which cannot be safely surrendered.

(Book 2 Chapter 63.1-2)

Empire as located its existence not in the smooth recurrent spinning time of the cycle of the seasons but in the jagged time of rise and fall, of beginning and end, of catastrophe.

A great empire cannot bring freedom by its own decay to those corners in it where a subject people are prevented from discussing the fundamentals of life. The people feel like children turned adrift to fend for themselves when the imperial routine breaks down; and they wander to and fro, given up to instinctive fears and antagonisms and exaltation until reason dares to take control. I had come to Yugoslavia to see what history meant in flesh and blood. I learned now that it might follow, because an empire passed, that a world full of strong men and women and rich food and heady wine might nevertheless seem like a shadow-show: that a man of every excellence might sit by a fire warming his hands in the vain hope of casting out a chill that lived not in the flesh.

History. The more of it you have the more you have to live it. After a little while there gets to be too much of it to memorize and maybe that's when empires start to decline.

HISTORY OF THE DECLINE AND FALL
OF THE ROMAN EMPIRE

the fate of an empire in many respects the most interesting in the world.

Even mighty states and kingdoms are not exempted. If we look into history, we shall find some nations rising from contemptible beginnings and spreading their influence, until the whole globe is subjected to their ways. When they have reached the summit of grandeur, some minute and unsuspected cause commonly affects their ruin, and the empire of the world is transferred to some other place. Immortal Rome was at first but an insignificant village, inhabited only by a few abandoned ruffians, but by degrees it rose to a stupendous height, and excelled in arts and arms all the nations that preceded it. But the demolition of Carthage (what one should think should have established is in supreme dominion) by removing all danger, suffered it to sink into debauchery, and made it at length an easy prey to Barbarians.

England immediately upon this began to increase (the particular and minute cause of which I am not historian enough to trace) in power and magnificence, and is now the greatest nation upon the globe.

Soon after the reformation a few people came over into the new world for conscience sake. Perhaps this (apparently) trivial incident may transfer the great seat of empire into America. It looks likely to me. For if we can remove the turbulent Gallics, our people according to exactest computations, will in another century, become more numerous than England itself. Should this be the case, since we have (I may say) all the naval stores of the nation in our hands, it will be easy to obtain the mastery of the seas, and then the united force of all Europe will not be able to subdue us. The only way to keep us from setting up for ourselves is to disunite us. Divide et impera. Keep us in distinct colonies, and then, some great men from each colony, desiring the monarchy of the whole, they will destroy each others' influence and keep the country in equilibrio.

Be not surprised that I am turned into politician. The whole town is immersed in politics.

The entire empire has sunk into a quagmire of extravagance from which they cannot extricate themselves.

Everything was there, it is simply that there was no clerk capable of making an inventory of all the constituents; but the realm that existed once — once and once only — had disappeared for ever, ground into infinitesimal pieces by the endless momentum of chaos within which crystals of order survived, the chaos that consisted of an indifferent and unstoppable traffic between things. It ground the empire into carbon, hydrogen, nitrogen and sulphur, it took its delicate fibres and unstitched them till they were dispersed and had ceased to exist, because they had been consumed by the force of some incomprehensibly distant edict, which must also consume this book, here, now, at the full stop, after the last word.

We like to see underdogs win. But there is no justice in history. Most past cultures have sooner or later fallen prey to the armies of some ruthless empire, which have consigned them to oblivion. Empires, too, ultimately fall, but they tend to leave behind rich and enduring legacies. Almost all people in the twenty-first century are the offspring of one empire or another.

loves are like empires: when the idea they are founded on crumbles, they, too, fade away.

The Western Empire, supported generation after generation by half a hundred of the strongest and most remarkable men in history, from Stilicho to Charlemagne, died and disintegrated and left off being the Empire.
The Eastern Empire, supported by fools and slaves and fops, and ruled by the worst and most incompetent of men and women, managed to endure and thrive for a thousand years more.

Your empire is now like a tyranny: it may have been wrong to take it; it is certainly dangerous to let it go.