This victory so greatly increased the reputation of Castruccio that Uguccione conceived some jealousy and suspicion of him, because it appeared to Uguccione that this victory had given him no increase of power, but rather than diminished it.  Being of this mind, he only waited for an opportunity to give effect to it.  This occurred on the death of Pier Agnolo Micheli, a man of great repute and abilities in Lucca, the murderer of whom fled to the house of Castruccio for refuge.  On the sergeants of the captain going to arrest the murderer, they were driven off by Castruccio, and the murderer escaped.  This affair coming to the knowledge of Uguccione, who was than at Pisa, it appeared to him a proper opportunity to punish Castruccio.  He therefore sent for his son Neri, who was the governor of Lucca, and commissioned him to take Castruccio prisoner at a banquet and put him to death.  Castruccio, fearing no evil, went to the governor in a friendly way, was entertained at supper, and then thrown into prison.  But Neri, fearing to put him to death lest the people should be incensed, kept him alive, in order to hear further from his father concerning his intentions.  Ugucionne cursed the hesitation and cowardice of his son, and at once set out from Pisa to Lucca with four hundred horsemen to finish the business in his own way; but he had not yet reached the baths when the Pisans rebelled and put his deputy to death and created Count Gaddo della Gherardesca their lord.  Before Uguccione reached Lucca he heard of the occurrences at Pisa, but it did not appear wise to him to turn back, lest the Lucchese with the example of Pisa before them should close their gates against him.  But the Lucchese, having heard of what had happened at Pisa, availed themselves of this opportunity to demand the liberation of Castruccio, notwithstanding that Uguccione had arrived in their city.  They first began to speak of it in private circles, afterwards openly in the squares and streets; then they raised a tumult, and with arms in their hands went to Uguccione and demanded that Castruccio should be set at liberty.  Uguccione, fearing that worse might happen, released him from prison.  Whereupon Castruccio gathered his friends around him, and with the help of the people attacked Uguccione; who, finding he had no resource but in flight, rode away with his friends to Lombardy, to the lords of Scale, where he died in poverty.

But Castruccio from being a prisoner became almost a prince in Lucca, and he carried himself so discreetly with his friends and the people that they appointed him captain of their army for one year.  Having obtained this, and wishing to gain renown in war, he planned the recovery of the many towns which had rebelled after the departure of Uguccione, and with the help of the Pisans, with whom he had concluded a treaty, he marched to Serezzana.  To capture this place he constructed a fort against it, which is called to-day Zerezzanello; in the course of two months Castruccio