[2] This claim of the House of Orleans to Milan was one source of French interference in Italian affairs.  Judged by Italian custom, Sforza’s claim through Bianca was as good as that of the Orleans princes through Valentina, since bastardy was no real bar in the peninsula.  It is said that Filippo Maria bequeathed his duchy to the Crown of Naples, by a will destroyed after his death.  Could this bequest have taken effect, it might have united Italy beneath one sovereign.  But the probabilities are that the jealousies of Florence, Venice, and Rome against Naples would have been so intensified as to lead to a bloody war of succession, and to hasten the French invasion.

The inextinguishable desire for liberty in Milan blazed forth upon the death of the last duke.  In spite of so many generations of despots, the people still regarded themselves as sovereign, and established a republic.  But a state which had served the Visconti for nearly two centuries, could not in a moment shake off its weakness and rely upon itself alone.  The republic, feeling the necessity of mercenary aid, was short-sighted enough to engage Francesco Sforza as commander-in-chief against the Venetians, who had availed themselves of the anarchy in Lombardy to push their power west of the Adda.

Sforza, though the ablest general of the day, was precisely the man whom common prudence should have prompted the burghers to mistrust.  In one brilliant campaign he drove the Venetians back beyond the Adda, burned their fleet at Casal Maggiore on the Po, and utterly defeated their army at Caravaggio.  Then he returned as conqueror to Milan, reduced the surrounding cities, blockaded the Milanese in their capital, and forced them to receive him as their Duke in 1450.  Italy had lost a noble opportunity.  If Florence and Venice had but taken part with Milan, and had stimulated the flagging energies of Genoa, four powerful republics in federation might have maintained the freedom of the whole peninsula and have resisted foreign interference.  But Cosimo de’ Medici, who was silently founding the despotism of his own family in Florence, preferred to see a duke in Milan; and Venice, guided by the Doge Francesco Foscari, thought only of territorial aggrandizement.  The chance was lost.  The liberties of Milan were extinguished.  A new dynasty was established in the duchy, grounded on a false hereditary claim, which, as long as it continued, gave a sort of color to the superior but still illegal pretensions of the house of Orleans.  It is impossible at this point in the history of Italy to refrain from judging that the Italians had become incapable of local self-government, and that the prevailing tendency to despotism was not the results of accidents in any combination, but of internal and inevitable laws of evolution.

It was at this period that the old despotisms founded by Imperial Vicars and Captains of the People came to be supplanted or crossed by those of military adventurers, just as at a somewhat later time the Condottiere and the Pope’s nominee were blent in Cesare Borgia.  This is therefore the proper moment for glancing at the rise and influence of mercenary generals in Italy, before proceeding to sketch the history of the Sforza family.