of them wishing to displace Manfred as long as he kept his promise of neutrality, and came under obligations to no one.  For these reasons, and also because the castle was well fortified, he had always been able to maintain his position.  It was here that Castruccio had determined to fall upon his enemy, for here his few men would have the advantage, and there was no fear lest, seeing the large masses of the hostile force before they became engaged, they should not stand.  As soon as this trouble with Florence arose, Castruccio saw the immense advantage which possession of this castle would give him, and having an intimate friendship with a resident in the castle, he managed matters so with him that four hundred of his men were to be admitted into the castle the night before the attack on the Florentines, and the castellan put to death.

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