Castruccio, having prepared everything, had now to encourage the Florentines to persist in their desire to carry the seat of war away from Pistoia into the Val di Nievole, therefore he did not move his army from Montecarlo.Thus the Florentines hurried on until they reached their encampment under Serravalle, intending to cross the hill on the following morning.In the meantime, Castruccio had seized the castle at night, had also moved his army from Montecarlo, and marching from thence at midnight in dead silence, had reached the foot of Serravalle: thus he and the Florentines commenced the ascent of the hill at the same time in the morning.Castruccio sent forward his infantry by the main road, and a troop of four hundred horsemen by a path on the left towards the castle.The Florentines sent forward four hundred cavalry ahead of their army which was following, never expecting to find Castruccio in possession of the hill, nor were they aware of his having seized the castle.Thus it happened that the Florentine horsemen mounting the hill were completely taken by surprise when they discovered the infantry of Castruccio, and so close were they upon it they had scarcely time to pull down their visors.It was a case of unready soldiers being attacked by ready, and they were assailed with such vigour that with difficulty they could hold their own, although some few of them got through.When the noise of the fighting reached the Florentine camp below, it was filled with confusion.The cavalry and infantry became inextricably mixed: the captains were unable to get their men either backward or forward, owing to the narrowness of the pass, and amid all this tumult no one knew what ought to be done or what could be done.In a short time the cavalry who were engaged with the enemy's infantry were scattered or killed without having made any effective defence because of their unfortunate position, although in sheer desperation they had offered a stout resistance.Retreat had been impossible, with the mountains on both flanks, whilst in front were their enemies, and in the rear their friends.When Castruccio saw that his men were unable to strike a decisive blow at the enemy and put them to flight, he sent one thousand infantrymen round by the castle, with orders to join the four hundred horsemen he had previously dispatched there, and commanded the whole force to fall upon the flank of the enemy.These orders they carried out with such fury that the Florentines could not sustain the attack, but gave way, and were soon in full retreat--conquered more by their unfortunate position than by the valour of their enemy.Those in the rear turned towards Pistoia, and spread through the plains, each man seeking only his own safety.The defeat was complete and very sanguinary.Many captains were taken prisoners, among whom were Bandini dei Rossi, Francesco Brunelleschi, and Giovanni della Tosa, all Florentine noblemen, with many Tuscans and Neapolitans who fought on the Florentine side, having been sent by King Ruberto to assist the Guelphs.Immediately the Pistoians heard of this defeat they drove out the friends of the Guelphs, and surrendered to Castruccio.He was not content with occupying Prato and all the castles on the plains on both sides of the Arno, but marched his army into the plain of Peretola, about two miles from Florence.Here he remained many days, dividing the spoils, and celebrating his victory with feasts and games, holding horse races, and foot races for men and women.He also struck medals in commemoration of the defeat of the Florentines.He endeavoured to corrupt some of the citizens of Florence, who were to open the city gates at night; but the conspiracy was discovered, and the participators in it taken and beheaded, among whom were Tommaso Lupacci and Lambertuccio Frescobaldi.This defeat caused the Florentines great anxiety, and despairing of preserving their liberty, they sent envoys to King Ruberto of Naples, offering him the dominion of their city; and he, knowing of what immense importance the maintenance of the Guelph cause was to him, accepted it.He agreed with the Florentines to receive from them a yearly tribute of two hundred thousand florins, and he send his son Carlo to Florence with four thousand horsemen.
Shortly after this the Florentines were relieved in some degree of the pressure of Castruccio's army, owing to his being compelled to leave his positions before Florence and march on Pisa, in order to suppress a conspiracy that had been raised against him by Benedetto Lanfranchi, one of the first men in Pisa, who could not endure that his fatherland should be under the dominion of the Lucchese.He had formed this conspiracy, intending to seize the citadel, kill the partisans of Castruccio, and drive out the garrison.As, however, in a conspiracy paucity of numbers is essential to secrecy, so for its execution a few are not sufficient, and in seeking more adherents to his conspiracy Lanfranchi encountered a person who revealed the design to Castruccio.
