There lived in the city of Lucca a gentleman of the Guinigi family, named Messer Francesco, whose profession was arms and who in riches, bodily strength, and valour excelled all other men in Lucca. He had often fought under the command of the Visconti of Milan, and as a Ghibelline was the valued leader of that party in Lucca. This gentleman resided in Lucca and was accustomed to assemble with others most mornings and evenings under the balcony of the Podesta, which is at the top of the square of San Michele, the finest square in Lucca, and he had often seen Castruccio taking part with other children of the street in those games of which I have spoken. Noticing that Castruccio far excelled the other boys, and that he appeared to exercise a royal authority over them, and that they loved and obeyed him, Messer Francesco became greatly desirous of learning who he was. Being informed of the circumstances of the bringing up of Castruccio he felt a greater desire to have him near to him. Therefore he called him one day and asked him whether he would more willingly live in the house of a gentleman, where he would learn to ride horses and use arms, or in the house of a priest, where he would learn nothing but masses and the services of the Church. Messer Francesco could see that it pleased Castruccio greatly to hear horses and arms spoken of, even though he stood silent, blushing modestly; but being encouraged by Messer Francesco to speak, he answered that, if his master were agreeable, nothing would please him more than to give up his priestly studies and take up those of a soldier. This reply delighted Messer Francesco, and in a very short time he obtained the consent of Messer Antonio, who was driven to yield by his knowledge of the nature of the lad, and the fear that he would not be able to hold him much longer.
Thus Castruccio passed from the house of Messer Antonio the priest to the house of Messer Francesco Guinigi the soldier, and it was astonishing to find that in a very short time he manifested all that virtue and bearing which we are accustomed to associate with a true gentleman. In the first place he became an accomplished horseman, and could manage with ease the most fiery charger, and in all jousts and tournaments, although still a youth, he was observed beyond all others, and he excelled in all exercises of strength and dexterity. But what enhanced so much the charm of these accomplishments, was the delightful modesty which enabled him to avoid offence in either act or word to others, for he was deferential to the great men, modest with his equals, and courteous to his inferiors. These gifts made him beloved, not only by all the Guinigi family, but by all Lucca. When Castruccio had reached his eighteenth year, the Ghibellines were driven from Pavia by the Guelphs, and Messer Francesco was sent by the Visconti to assist the Ghibellines, and with him went Castruccio, in charge of his forces. Castruccio gave ample proof of his prudence and courage in this expedition, acquiring greater reputation than any other captain, and his name and fame were known, not only in Pavia, but throughout all Lombardy.
Castruccio, having returned to Lucca in far higher estimation than he left it, did not omit to use all the means in his power to gain as many friends as he could, neglecting none of those arts which are necessary for that purpose. About this time Messer Francesco died, leaving a son thirteen years of age named Pagolo, and having appointed Castruccio to be his son’s tutor and administrator of his estate. Before he died Francesco called Castruccio to him, and prayed him to show Pagolo that goodwill which he (Francesco) had always shown to HIM, and to render to the son the gratitude which he had not been able to repay to the father. Upon the death of Francesco, Castruccio became the governor and tutor of Pagolo, which increased enormously his power and position, and created a certain amount of envy against him in Lucca in place of the former universal goodwill, for many men suspected him of harbouring tyrannical intentions. Among these the leading man was Giorgio degli Opizi, the head of the Guelph party. This man hoped after the death of Messer Francesco to become the chief man in Lucca, but it seemed to him that Castruccio, with the great abilities which he already showed, and holding the position of governor, deprived him of his opportunity; therefore he began to sow those seeds which should rob Castruccio of his eminence. Castruccio at first treated this with scorn, but afterwards he grew alarmed, thinking that Messer Giorgio might be able to bring him into disgrace with the deputy of King Ruberto of Naples and have him driven out of Lucca.
The Lord of Pisa at that time was Uguccione of the Faggiuola of Arezzo, who being in the first place elected their captain afterwards became their lord. There resided in Paris some exiled Ghibellines from Lucca, with whom Castruccio held communications with the object of effecting their restoration by the help of Uguccione. Castruccio also brought into his plans friends from Lucca who would not endure the authority of the Opizi. Having fixed upon a plan to be followed, Castruccio cautiously fortified the tower of the Onesti, filling it with supplies and munitions of war, in order that it might stand a siege for a few days in case of need. When the night came which had been agreed upon with Uguccione, who had occupied the plain between the mountains and Pisa with many men, the signal was given, and without being observed Uguccione approached the gate of San Piero and set fire to the portcullis. Castruccio raised a great uproar within the city, calling the people to arms and forcing open the gate from his side. Uguccione entered with his men, poured through the town, and killed Messer Giorgio with all his family and many of his friends and supporters. The governor was driven out, and the government reformed according to the wishes of Uguccione, to the detriment of the city, because it was found that more than one hundred families were exiled at that time. Of those who fled, part went to Florence and part to Pistoia, which city was the headquarters of the Guelph party, and for this reason it became most hostile to Uguccione and the Lucchese.
As it now appeared to the Florentines and others of the Guelph party that the Ghibellines absorbed too much power in Tuscany, they determined to restore the exiled Guelphs to Lucca. They assembled a large army in the Val di Nievole, and seized Montecatini; from thence they marched to Montecarlo, in order to secure the free passage