The growing dissensions in the Guelf Republic came to a head in 1300, the famous year of jubilee in which the Pope was said to have declared that the Florentines were the "fifth element." The rival factions of Bianchi and Neri, White Guelfs and Black Guelfs, which were now to divide the whole city, arose partly from the deadly hostility of two families each with a large following, the Cerchi and the Donati, headed respectively by Vieri dei Cerchi and Corso Donati, the two heroes of Campaldino; partly from an analogous feud in Pistoia, which was governed from Florence; partly from the political discord between that party in the State that clung to the (modified) Ordinances of Justice and supported the Signoria, and another party that hated the Ordinances and loved the tyrannical Parte Guelfa. They were further complicated by the intrigues of the "black" magnates with Pope Boniface VIII., who apparently hoped by their means to repress the burgher government and unite the city in obedience to himself. With this end in view, he had been endeavouring to obtain from Albert of Austria the renunciation, in favour of the Holy See, of all rights claimed by the Emperors over Tuscany. Dante himself, Guido Cavalcanti, and most of the best men in Florence either directly adhered to, or at least favoured, the Cerchi and the Whites; the populace, on the other hand, was taken with the dash and display of the more aristocratic Blacks, and would gladly have seen Messer Corso--"il Barone," as they called him--lord of the city. Rioting, in which Guido Cavalcanti played a wild and fantastic part, was of daily occurrence, especially in the Sesto di San Piero. The adherents of the Signoria had their head-quarters in the Cerchi Palace, in the Via della Condotta; the Blacks found their legal fortress in that of the Captains of the Parte Guelfa in the Via delle Terme. At last, on May 1st, the two factions "came to blood" in the Piazza di Santa Trinità on the occasion of a dance of girls to usher in the May. On June 15th Dante was elected one of the six Priors, to hold office till August 15th, and he at once took a strong line in resisting all interference from Rome, and in maintaining order within the city. In consequence of an assault upon the officers of the Guilds on St. John's Eve, the Signoria, probably on Dante's initiative, put under bounds a certain number of factious magnates, chosen impartially from both parties, including Corso Donati and Guido Cavalcanti. From his place of banishment at Sarzana, Guido, sick to death, wrote the most pathetic of all his lyrics:-- "Because I think not ever to return, Ballad, to Tuscany,-- Go therefore thou for me Straight to my lady's face, Who, of her noble grace, Shall show thee courtesy. * * * * *