And truly thus was fulfilled the prophecy and revelation made to him by the devil by means of incantation, though he did not understand it; for having invoked him to learn how he would fare in that expedition, he made a lying answer and said, "Thou wilt go and fight; thou goest to conquer not to die in the battle, and thy head shall be the highest in the field;" and he, thinking to have the victory from these words, and thinking he would remain lord over all, did not put the stop in the right place and detect the fraud, where he said, "Thou goest to conquer not, to die," etc. And therefore it is great folly to believe in such counsel as is that of the devil. This M. Provenzano was a great man in Siena in his day after the victory which he gained at Montaperti, and he ruled all the city; and all the Ghibelline party in Tuscany made him their head, and he was very presumptuous in will. In this battle the said M. Giambertaldo bore himself like a valiant lord in fighting against his enemies, and likewise did his followers and all the Guelfs of Florence, making great slaughter of their enemies to avenge their kinsfolk and friends which were slain at the defeat of Montaperti; and none, or scarce any, did they lead to prison, but put them all to death and to the sword; wherefore the city of Siena, in comparison with the number of its inhabitants, suffered greater loss of its citizens in this defeat than Florence did on the day of Montaperti; and they left on the field all their belongings. For the which thing a little while after, the Florentines restored the Guelf refugees to Siena and drave out the Ghibellines and made peace between one commonwealth and the other, remaining ever after friends and allies. And in this manner ended the war between the Florentines and the Sienese which had endured so long. [Sidenote: 1269 A.D.] Sec. 32.--_How the Florentines took the castle of Ostina in Valdarno._ Sec. 33.--_How the Florentines, serving for the Lucchese, marched upon Pisa._ Sec. 34.--_How there was a great flood of waters which carried away the Santa Trinita Bridge and the Carraia Bridge._ [Sidenote: 1269 A.D.]