The Archbishop Ruggieri dissimulated for a while, waiting his chance to take revenge. It came at last. On July 1, 1288, the council of the Republic was assembled in the Church of St. Sebastian to discuss the arrangement of peace with Genoa. Both the Ghibellines and people yearned for peace at any cost; but the count raised fresh obstacles, still relying on the support of his friends. As the meeting dispersed, the archbishop perceived that the favourable moment had arrived, and that no time must be lost. The Gualandi, Sismondi, Lanfranchi and other houses joined with him, and all proceeded to attack Ugolino. The latter made a valiant resistance, aided by two of his sons, two nephews, and a few devoted followers. After the first encounter, in which Ugolino's natural son was slain before his eyes, he took refuge in the palace of the people, and defended it from midday to dusk, when the besiegers decided to set it on fire. Then, forcing their way through the flames, they captured the count, with his two younger sons, Gaddo and Uguccione, and his nephews Nino, surnamed Brigata, and Anselmuccio. The prisoners were thrown into the Gualandi tower on the Piazza degli Anziani, and Ruggieri kept them most closely confined there for several months.[325] Finally the key of the tower was cast into the Arno, and all left to die of starvation, amid the torments immortalised by Dante's pen.[326] IX. These events, while still further reducing the strength of the unfortunate city, likewise caused the overthrow of the Pisan Guelphs, by once more driving them into exile, and promoted the hopes of the Ghibellines, who now seemed to have gained new life in Tuscany. Accordingly Florence was again compelled to recur to arms. Charles I of Anjou was no more, and Pope Honorius, being favourable to the Ghibellines, had instigated his kinsman, Prenzivalle del Fiesco, to assume the post of vicar-imperial in Tuscany, But as the cities of the League gave him a very rough reception, he retired to Arezzo, and vainly promulgated edicts against the Guelphs. By this time no one heeded the words of Imperial vicars. On realising this he went back to Germany, leaving Arezzo a prey to conflicts, in which the Ghibellines won the victory, with the help of numerous Florentine exiles. The Guelphs sought refuge in neighbouring castles, whither reinforcements reached them from the Florentine Signory. Thus the war spread even to the Upper Val d'Arno; for as the Ghibellines had returned to power, both in Arezzo and Pisa, led by the spiritual lord of either town, they had now to be encountered on two sides. In Pisa their chief was the Archbishop Ubaldini, in Arezzo, Guglielmo degli Ubertini, an equally Ghibelline prelate. The latter was also a better warrior than priest, the lord of many strongholds, and being of a very slippery nature, first attempted to betray the city to the Florentines, in return for an agreement guaranteeing him his possessions. The men of Arezzo