It was soon known in Florence that the duke was preparing to send forces into Tuscany.  This made the Florentines apprehensive for the success of their enterprise; and in order to retain the duke in Lombardy, they requested the Venetians to press him with their utmost strength.  But they also were alarmed, the marquis of Mantua having abandoned them and gone over to the duke; and thus, finding themselves almost defenseless, they replied, “that instead of increasing their responsibilities, they should be unable to perform their part in the war, unless the Count Francesco were sent to them to take the command of the army, and with the special understanding that he should engage to cross the Po in person.  They declined to fulfil their former engagements unless he were bound to do so; for they could not carry on the war without a leader, or repose confidence in any except the count; and he himself would be useless to them, unless he came under an obligation to carry on the war whenever they might think needful.”  The Florentines thought the war ought to be pushed vigorously in Lombardy; but they saw that if they lost the count their enterprise against Lucca was ruined; and they knew well that the demand of the Venetians arose less from any need they had of the count, than from their desire to frustrate this expedition.  The count, on the other hand, was ready to pass into Lombardy whenever the league might require him, but would not alter the tenor of his engagement; for he was unwilling to sacrifice the hope of the alliance promised to him by the duke.

The Florentines were thus embarrassed by two contrary impulses, the wish to possess Lucca, and the dread of a war with Milan.  As commonly happens, fear was the most powerful, and they consented, after the capture of Uzzano, that the count should go into Lombardy.  There still remained another difficulty, which, depending on circumstances beyond the reach of their influence, created more doubts and uneasiness than the former; the count would not consent to pass the Po, and the Venetians refused to accept him on any other condition.  Seeing no other method of arrangement, than that each should make liberal concessions, the Florentines induced the count to cross the river by a letter addressed to the Signory of Florence, intimating that this private promise did not invalidate any public engagement, and that he might still refrain from crossing; hence it resulted that the Venetians, having commenced the war, would be compelled to proceed, and that the evil apprehended by the Florentines would be averted.  To the Venetians, on the other hand, they averred that this private letter was sufficiently binding, and therefore they ought to be content; for if they could save the count from breaking with his father-in-law, it was well to do so, and that it could be of no advantage either to themselves or the Venetians to publish it without some manifest necessity.  It was thus determined that the count should pass into Lombardy;