Guelphs and Ghibellines: Circle 6, Inferno 10   While the Florentine political parties of Dante's day were the white and black guelphs--the blacks more favorable to interests of the old noble class, the whites more aligned with the rising merchant class--Florence before Dante's childhood participated in the more general political struggle between guelphs and ghibellines on the Italian peninsular and in other parts of Europe. Derived from two warring royal houses in Germany (Waiblingen and Welf), the sides came to be distinguished by their adherence to the claims of the emperor (ghibellines) or the pope (guelph). The guelph cause finally triumphed with the death of Manfred--son of Emperor Frederick II--at the battle of Benevento (in southern Italy) in 1266. Until this time, Florence alternated between guelph and ghibelline rule, beginning--according to medieval chronicles--with a violent conflict between two prominent families and their allies in 1215: young Buondelmonte de' Buondelmonti, the story goes, was murdered by the Amidei clan on Easter Sunday after he broke his promise to marry an Amidei (as part of a peace arrangement) and married one of the Donati instead. This event came to be seen as the origin of the factional violence that would plague Florence for the next century and beyond.