The Sieges of Rome - Brennus and the Colony of Gauls

One of the great objects of history is to form character by placing acts of patriotic devotion or private virtue in the most attractive light... From the way in which what is called Rome, as a nation, was got together, it was naturally in a constant state of warfare. The spirit in which it was founded pervaded and ruled over it to its fall: it was at all times a nation of the sword; and when that sword was blunted by having conquered the known world, its conquests all crumbled away: when Rome ceased to be an aggressor, she instantly ceased to be great.
Rome, of course, commenced this aggressive career with wars upon her neighbours, a cause for quarrel being quickly and easily found where everything was to be gained and little to be lost. Thus, the rape of the Sabine women produced the first siege of the nascent city, a violation not only of the laws of nations, but of the laws of even the rudest state of nature, created its first enemies.