Battle of Monaperti 1260, Florentine Chronicle of Giovanni Villani (early 14 th C)

Florentine & Tuscan Guelfs prepare to attack Ghibelline Siena: When the army was assembled, it departed at the end of August. With pomp and circumstance they led forth the carroccio and a bell which they called Martinella, the latter being placed on a cart with a wooden castle on wheels. Almost all the people went bearing the standards of the guilds, and there was not a house or family in Florence from which at least one person and sometimes two or more (according to their power) did not go forth on foot or horseback. And when they found themselves in Sienese territory, at the designated spot on the river Arbia, in the place called Montaperti, with the Perugians and Orvietans who joined them there, they had over three thousand knights and thirty thousand foot-soldiers. …

Once the Florentine army was established in the hills of Montaperti … an eminent Ghibelline named Razzante, from the Porta San Pietro section in Florence… withthe consent of other Ghibellines in the army (who had treason on their minds),  fled from the Florentine camp on horseback and went to Siena. His mission was to inform  Florentine exiles there that the city was to be betrayed and that the Florentines were well provided with knights and foot-soldiers. He advised those within not to recommend battle.

When the plotters Farinata [degli Uberti, Inf 10] and Gherardo heard his message, they said to him, "You'll kill us if you spread this news around Siena, because you'll frighten them. We want you to say just the opposite. If we don't fight while we have these Germans [Imperial troops], we're dead! We'll never get back to Florence. Death and defeat would be better for us than to go begging around the world any longer." They preferred to stake their future on one decisive battle.

Having been set straight by Farinata and Gherardo, Razzante promised to speak as they suggested. With a garland on his head and a very cheerful expression on his face, he and the other two rode on horseback to a meeting at the palace, where all the people of Siena, the Germans and other allies were gathered. There he joyfully announced the great news from the traitors in the Florentine camp. The army, he said, was ill-prepared, poorly-led and disunited. A determined attack would defeat them. When Razzante had delivered his false report, the Sienese all armed, shouting "battle, battle!" The Germans asked and received a promise of double pay, and their group led the assault through the San Vito gate, the very one that was supposed to be given to the Florentines [by Siennese Guelfs who sympathized with Guelf Florence]. The other knights and people followed close behind them.

The German troops violently collided with Florentine knights at the point where the standard of the communal cavalry was being carried by Iacopo del Nacca of the house of Pazzi, a man of great valor; the traitor Bocca degli Abati [Inf 32] who was near lacopo in his troop, struck him with his sword and cut off the hand with which he held the standard; Iacopo soon died. Seeing their standard fallen, themselves betrayed and strongly attacked by the Germans, the Florentine knights and people were soon routed.

Because the cavalry was the first group to become aware of the treason, only thirty-six of them were among the dead and captured. Most of the slaughter and captivity was sustained by the Florentine foot-soldiers and by men of Lucca and Orvieto, who shut themselves up in the castle of Montaperti and were all taken. Over 2500 were left dead on the field and more than 1500 were captured, some of the best people in Florence, men from every house, as well as other allies. Thus the arrogance of the ungrateful and proud Florentine people was brought low. This was on a Tuesday, September 4th, in the year of Christ 1260, and the carroccio and bell called Martinella were left behind along with uncountable booty from the baggage of the Florentines and their allies. Thus ended the primo popolo [first popular government or merchant guild regime] of Florence, which had exercised such great lordship and won so many victories over its ten-year period (1250-60).

When news of the grievous defeat reached Florence along with those who had escaped, there arose among men and women a wail of lament so powerful that it reached up to heaven, for there was no house in Florence, small or great, from which someone had not been killed or captured. ... The Guelf leaders were afraid the exiles would soon arrive from Siena with the Germans, and they knew that rebellious Ghibellines were already returning to the area. Thus the Guelfs, without being banished or chased out, went weeping from Florence along with their families and settled in Lucca. It was Thursday the thirteenth of September, in the year of Christ 1260.  

Excerpt from Medieval Sourcebook, Villani, Florentine Chronicle, <http://www.fordham.edu/halsall/source/villani.html>