During the long struggle between the Guelf (papal) and the Ghibelline (imperial) parties for supremacy in the city, Dante's family's participation in the political life of Guelf Florence was of only minor importance. Bellincione and Alighiero do not appear among the names of those suffering hardship (as Guelf supporters) under the Ghibellines in their period of power between 1260 and 1266; moreover, Dante's father, after the Guelf defeat of Montaperti (1260), seems not to have been sent into exile by the Ghibellines. "The great town on the fair river of the Arno" was, by the time of the poet's birth, already devoting its energies to territorial and economic expansion, and he deemed this to be the principal cause of the internal discord afflicting the commune from 1216 onward. He described, in an episode of the Paradiso relating to Cacciaguida, how the steady infiltration of the feudal nobility into the city's economic and political life had been a root cause of the great di-visions and dislocations that shook medieval Florence. It had caused the magnates themselves to split into Guelf and Ghibelline factions, provoked the rich Guelf bour-geoisie's struggle against the magnates (with the former emerging powerful between 1250 and 1260); and had at last resulted in Guelf dominance after 1266, when Charles I of Anjou defeated and slew Manfred the im-perial claimant at the Battle of Benevento. From then on Florence remained within the sphere of Angevin and papal control but not without fierce social strife, re-sulting from the antimagnate politics of the Guelf commune. Unrest was further aggravated by external con-flicts caused by campaigns of territoral conquest. Such was the background of events known to the young Dante that in their later development were to provoke active participation by the mature poet. Dante grew up &endash; after the death of his mother, Bella (probably of the Abati family), and the remarriage of his father to Lapa di Chiarissimo Cialuffi - in the company of an older sister and a half brother, Francesco, and half sister, Gaetana, from his father's second marriage.