This event, although an act of great temerity, and attended with the result that usually follows such attempts, raised a hope in the minds of the nobility of overcoming the people, seeing that the lowest of the plebeians were at enmity with them.  And to profit by this circumstance, they resolved to arm themselves, and with justifiable force recover those rights of which they had been unjustly deprived.  Their minds acquired such an assurance of success, that they openly provided themselves with arms, fortified their houses, and even sent to their friends in Lombardy for assistance.  The people and the Signory made preparation for their defense, and requested aid from Perugia and Sienna, so that the city was filled with the armed followers of either party.  The nobility on this side of the Arno divided themselves into three parts; the one occupied the houses of the Cavicciulli, near the church of St. John; another, the houses of the Pazzi and the Donati, near the great church of St. Peter; and the third those of the Cavalcanti in the New Market.  Those beyond the river fortified the bridges and the streets in which their houses stood; the Nerli defended the bridge of the Carraja; the Frescobaldi and the Manelli, the church of the Holy Trinity; and the Rossi and the Bardi, the bridge of the Rubaconte and the Old Bridge.  The people were drawn together under the Gonfalon of justice and the ensigns of the companies of the artisans.

Both sides being thus arranged in order of battle, the people thought it imprudent to defer the contest, and the attack was commenced by the Medici and the Rondinelli, who assailed the Cavicciulli, where the houses of the latter open upon the piazza of St. John.  Here both parties contended with great obstinacy, and were mutually wounded, from the towers by stones and other missiles, and from below by arrows.  They fought for three hours; but the forces of the people continuing to increase, and the Cavicciulli finding themselves overcome by numbers, and hopeless of other assistance, submitted themselves to the people, who saved their houses and property; and having disarmed them, ordered them to disperse among their relatives and friends, and remain unarmed.  Being victorious in the first attack, they easily overpowered the Pazzi and the Donati, whose numbers were less than those they had subdued; so that there only remained on this side of the Arno, the Cavalcanti, who were strong both in respect of the post they had chosen and in their followers.  Nevertheless, seeing all the Gonfalons against them, and that the others had been overcome by three Gonfalons alone, they yielded without offering much resistance.  Three parts of the city were now in the hands of the people, and only one in possession of the nobility; but this was the strongest, as well on account of those who held it, as from its situation, being defended by the Arno; hence it was first necessary to force the bridges.  The Old Bridge was first assailed and offered a brave resistance;