Of all prophecies, none are, perhaps, so frequently erroneous as those on which we are most apt to venture in endeavouring to foretell the effect of outward events on the characters of men. In no form of our anticipations are we more frequently baffled than in such attempts to estimate beforehand the influence of circumstance over conduct, not only in others, but also even in ourselves. Let the event but happen, and men, whom we view by the light of our previous observation of them, act under it as the living contradictions of their own characters. The friend of our daily social intercourse, in the progress of life, and the favourite hero of our historic studies, in the progress of the page, astonish, exceed, or disappoint our expectations alike. We find it as vain to foresee a cause as to fix a limit for the arbitrary inconsistencies in the dispositions of mankind. But, though to speculate upon the future conduct of others under impending circumstances be but too often to expose the fallacy of our wisest anticipations, to contemplate the nature of that conduct after it has been displayed is a useful subject of curiosity, and may perhaps be made a fruitful source of instruction. Similar events which succeed each other at different periods are relieved from monotony, and derive new importance from the ever-varying effects which they produce on the human character. Thus, in the great occurrence which forms the foundation of our narrative, we may find little in the siege of Rome, looking at it as a mere event, to distinguish it remarkably from any former siege of the city--the same desire for glory and vengeance, wealth and dominion, which brought Alaric to her walls, brought other invaders before him. But if we observed the effect of the Gothic descent upon Italy on the inhabitants of her capital, we shall find ample matter for novel contemplation and unbounded surprise.