But the freedom of Pisa was gone for ever; others, lords and tyrants, arose, Castruccio Castracani and the rest, yet she was still at bay.  On the 2nd October 1325 she again defeated Florence at Altopascio, and even excluded her from the port, and, in 1341, when Florence had bought Lucca from Mastino della Scala for 250,000 florins, she besieged it to prevent the entry of the Florentine army then aided by Milan, Mantova, and Padova, In 1342, the Florentines having failed to relieve Lucca, the Pisans entered the city.  The possession of Lucca seemed to put Pisa, where centuries ago Luitprand had placed her, at the head of the province of Tuscany.  This view, which certainly she herself was not slow to take, was confirmed when Volterra and Pistoja placed themselves under her protection; yet, as ever, her greatest danger was the discord within her walls.  The Republic was weak, nearly a million and a half of florins had been spent on the war, and many tyrants were her allies; moreover, she had lent troops to Milan.[37] It was this moment of reaction after so great an effort that Visconti d’Oleggio chose for a conspiracy against Gherardesca the Captain-General.  It is true the plot was discovered, the traitors exiled, and Visconti banished; but the mischief was done.  When Lucchino Visconti heard of it in Milan, he imprisoned the Pisan troops in that city and sent Visconti d’Oleggio back with two thousand men to seize Pisa.  Thus the war dragged on; and though these Milanese were destroyed for the most part by malaria in the Maremma, still Pisa had no rest.  After Visconti came famine, and after the famine the Black Death.  Seventy in every hundred of the population died, Tronci tells us,[38] while during the famine, bread, such as it was, had to be distributed every day at the taverns.  Then followed a revolution in the city.  Count Raniero of the Gherardesca house had succeeded to the Captain-Generalship of Pisa as though it were his right by birth.  This brought him many enemies; and, indeed, the city was in uproar for some years:  for, while he was so young, Dino della Rocca acted for him.  Among the more powerful enemies of della Rocca was Andrea Gambacorti, whose family was soon to enslave the city.  Now the one party was called Bergolini, for they had named Raniero Bergo for hate, and of these Gambacorti was chief.  The other party which was at this time in power, as I have said, was named Raspanti, which is to say graspers, and of them Dino della Rocca was head.  In the midst of this disputing Raniero died, and the Raspanti were accused of having murdered him, among others by Gambacorti.  Every sort of device to heal these wounds was resorted to; marriages and oaths all alike failed.  The city blazed with their arson every night, till at last the people rose and expelling the Raspanti, chose Andrea Gambacorti for captain.  This happened in 1348.  Seven years later, Charles IV, on his way to Rome to be crowned, came to the city.  Now the Conte di Montescudaio