of the case, sent Tommaso Soderini as their ambassador to the senate, and, in the meantime, engaged forces, and appointed Ercole, marquis of Ferrara, to the command of their army.  While these preparations were being made, the Castellina was so hard pressed by the enemy, that the inhabitants, despairing of relief, surrendered, after having sustained a siege of forty-two days.  The enemy then directed their course toward Arezzo, and encamped before San Savino.  The Florentine army being now in order, went to meet them, and having approached within three miles, caused such annoyance, that Federigo d’Urbino demanded a truce for a few days, which was granted, but proved so disadvantageous to the Florentines, that those who had made the request were astonished at having obtained it; for, had it been refused, they would have been compelled to retire in disgrace.  Having gained these few days to recruit themselves, as soon as they were expired, they took the castle in the presence of their enemies.  Winter being now come, the forces of the pope and king retired for convenient quarters to the Siennese territory.  The Florentines also withdrew to a more commodious situation, and the marquis of Ferrara, having done little for himself and less for others, returned to his own territories.

At this time, Genoa withdrew from the dominion of Milan, under the following circumstances.  Galeazzo, at his death, left a son, Giovan Galeazzo, who being too young to undertake the government, dissensions arose between Sforza, Lodovico, Ottaviano, and Ascanio, his uncles, and the lady Bona, his mother, each of whom desired the guardianship of the young duke.  By the advice and mediation of Tommaso Soderini, who was then Florentine ambassador at the court of Milan, and of Cecco Simonetta, who had been secretary to Galeazzo, the lady Bona prevailed.  The uncles fled, Ottaviano was drowned in crossing the Adda; the rest were banished to various places, together with Roberto da San Severino, who in these disputes had deserted the duchess and joined the uncles of the duke.  The troubles in Tuscany, which immediately followed, gave these princes hope that the new state of things would present opportunities for their advantage; they therefore quitted the places to which their exile limited them, and each endeavored to return home.  King Ferrando, finding the Florentines had obtained assistance from none but the Milanese, took occasion to give the duchess so much occupation in her own government, as to render her unable to contribute to their assistance.  By means of Prospero Adorno, the Signor Roberto, and the rebellious uncles of the duke, he caused Genoa to throw off the Milanese yoke.  The Castelletto was the only place left; confiding in which, the duchess sent a strong force to recover the city, but it was routed by the enemy; and perceiving the danger which might arise to her son and herself if the war were continued, Tuscany being in confusion, and the Florentines, in whom alone she had hope, themselves