This quarrel, and the parties in it, brought from Pistoia, increased the old animosity between the Cerchi and the Donati, and it was already so manifest, that the Priors and all well-disposed men were in hourly apprehension of its breaking out, and causing a division of the whole city.  They therefore applied to the pontiff, praying that he would interpose his authority between these turbulent parties, and provide the remedy which they found themselves unable to furnish.  The pope sent for Veri, and charged him to make peace with the Donati, at which Veri exhibited great astonishment, saying that he had no enmity against them, and that as pacification presupposes war, he did not know, there being no war between them, how peacemaking could be necessary.  Veri having returned from Rome without anything being effected, the rage of the parties increased to such a degree, that any trivial accident seemed sufficient to make it burst forth, as indeed presently happened.

It was in the month of May, during which, and upon holidays, it is the custom of Florence to hold festivals and public rejoicings throughout the city.  Some youths of the Donati family, with their friends, upon horseback, were standing near the church of the Holy Trinity to look at a party of ladies who were dancing; thither also came some of the Cerchi, like the Donati, accompanied with many of the nobility, and, not knowing that the Donati were before them, pushed their horses and jostled them; thereupon the Donati, thinking themselves insulted, drew their swords, nor were the Cerchi at all backward to do the same, and not till after the interchange of many wounds, they separated.  This disturbance was the beginning of great evils; for the whole city became divided, the people as well as the nobility, and the parties took the names of the Bianchi and the Neri.  The Cerchi were at the head of the Bianchi faction, to which adhered the Adimari, the Abati, a part of the Tosinghi, of the Bardi, of the Rossi, of the Frescobaldi, of the Nerli, and of the Manelli; all the Mozzi, the Scali, Gherardini, Cavalcanti, Malespini, Bostichi, Giandonati, Vecchietti, and Arrigucci.  To these were joined many families of the people, and all the Ghibellines then in Florence, so that their great numbers gave them almost the entire government of the city.

The Donati, at the head of whom was Corso, joined the Nera party, to which also adhered those members of the above-named families who did not take part with the Bianchi; and besides these, the whole of the Pazzi, the Bisdomini, Manieri, Bagnesi, Tornaquinci, Spini, Buondelmonti, Gianfigliazzi, and the Brunelleschi.  Nor did the evil confine itself to the city alone, for the whole country was divided upon it, so that the Captains of the Six Parts, and whoever were attached to the Guelphic party or the well-being of the republic, were very much afraid that this new division would occasion the destruction of the city, and give new life to the Ghibelline faction.  They, therefore,