at one another across the Valdichiana, Perugia rears a tower against Chiusi, and Chiusi builds her Becca Questa in responsive menace.  The tiniest burgh upon the Arno receives from Dante, the poet of this internecine strife and fierce town-rivalry, its stigma of immortalizing satire and insulting epithet, for no apparent reason but that its dwellers dare to drink of the same water and to breathe the same air as Florence.  It would seem as though the most ancient furies of antagonistic races, enchained and suspended for centuries by the magic of Rome, had been unloosed; as though the indigenous populations of Italy, tamed by antique culture, were reverting to their primal instincts, with all the discords and divisions introduced by the military system of the Lombards, the feudalism of the Franks, the alien institutions of the Germans, superadded to exasperate the passions of a nation blindly struggling against obstacles that block the channel of continuous progress.  Nor is this the end of the perplexity.  Not only are the cities at war with one another, but they are plunged in ceaseless strife within the circuit of their ramparts.  The people with the nobles, the burghs with the castles, the plebeians with the burgher aristocracy, the men of commerce with the men of arms and ancient lineage, Guelfs and Ghibellines, clash together in persistent fury.  One half the city expels the other half.  The exiles roam abroad, cement alliances, and return to extirpate their conquerors.  Fresh proscriptions and new expulsions follow.  Again alliances are made and revolutions accomplished, till the ancient feuds of the towns are crossed, recrossed, and tangled in a web of madness that defies analysis.  Through the medley of quarreling, divided, subdivided, and intertwisted factions, ride Emperors followed by their bands of knights, appearing for a season on vain quests, and withdrawing after they have tenfold confounded the confusion.  Papal Legates drown the cities of the Church in blood, preach crusades, fulminate interdictions, rouse insurrections in the States that own allegiance to the Empire.  Monks stir republican revivals in old cities that have lost their liberties, or assemble the populations of crime-maddened districts in aimless comedies of piety and false pacification, or lead them barefooted and intoxicated with shrill cries of ‘Mercy’ over plain and mountain.  Princes of France, Kings of Bohemia and Hungary, march and countermarch from north to south and back again, form leagues, establish realms, head confederations, which melt like shapes we form from clouds to nothing.  At one time the Pope and Emperor use Italy as the arena of a deadly duel, drawing the congregated forces of the nation into their dispute.  At another they join hands to divide the spoil of ruined provinces.  Great generals with armies at their backs start into being from apparent nothingness, dispute the sovereignty of Italy in bloodless battles, found ephemeral dynasties, and pass away like mists upon a mountain-side beneath a puff of wind.  Conflict, ruin, desolation, anarchy are ever yielding place to concord, restoration, peace, prosperity, and then recurring with a mighty flood of violence.  Construction, destruction, and reconstruction play their part in crises that have to be counted by the thousands.