No city in Italy had been more convulsed than Florence [Sidenote: Constitution of Florence.] by the struggle between Guelfs and Ghibellines, and these factions were the more embittered against each other by their coincidence with class distinctions. The feudal nobles, although by no means united, were preponderantly Ghibelline, while the wealthy burghers were inclined to the cause of the Papacy and Charles of Anjou. After the defeat of Manfred in 1266 the supremacy of the Guelfs was established, and was never overthrown from that date. For some years the government was moderate and pacific, but the news of the Sicilian Vespers in 1282 frightened the Guelfs into an attempt to secure their power by constitutional changes. The existing magistrates were superseded [Sidenote: The ‘Priori.’] by the ‘_Priori delle Arti_,’ at first three and afterwards six in number. These constituted the signory and held the chief executive power. They were chosen from the seven greater guilds (_arti maggiori_) and held office for two months at a time, re-election being forbidden (_divieto_) until after an interval of two years. The greater guilds, which had long existed as trade corporations before their rise to political importance, consisted of the _Calimala_, or cloth merchants, the wool-weavers, the bankers, the silk manufacturers, physicians, furriers and lawyers. About the same time a number of lesser guilds (_arti minori_) were organised, and their number increased within the next sixteen years to fourteen. Henceforth we can trace the existence of four main divisions of the people of Florence: (1) the _grandi_, or nobles; (2) the _popolo grasso_, the members of the seven greater guilds; (3) the _popolo minuto_, or members of the fourteen lesser guilds; (4) the _ciompi_, though this name is of later origin, including those citizens who had no guild organisation, and therefore no machinery either for self-government or for influencing the conduct of public business.