The Commonwealth, busy in resettling its government, was but slightly interested in much that went on around it. The boy Conradin, grandson of Frederick, nephew of Manfred, and in a sense the last of the Hohenstaufens, came to Italy to measure himself with Charles, and paid for his audacity upon the scaffold.[23] Charles deputed Guy of Montfort, son of the great Earl Simon, to be his vicar in Florence. The Pope smiled and frowned in turn on the Florentines, as their devotion to him waxed and waned; and so he did on his champion Charles, whose ambition was apt to outrun his piety. All this was of less importance to the Commonwealth than the promotion of its domestic interests. It saw with equanimity a check given to Charles by the election of a new Emperor in Rudolf of Hapsburg (1273), and a further check by the Sicilian Vespers, which lost him half his kingdom (1283). But Siena and Pisa, Arezzo, and even Pistoia, were the objects of a sleepless anxiety. Pisa was the chief source of danger, being both from sentiment and interest stubbornly Ghibeline. When at length its power was broken by Genoa, its great maritime rival, in the naval battle of Meloria (1284), there was no longer any city in Tuscany to be compared for wealth and strength with Florence. III. It was at this period that Dante, reaching the age of manhood, began to perform the duties that fell to him as a youthful citizen--duties which, till the age of thirty was reached, were chiefly those of military service. The family to which he belonged was a branch of the Elisei, who are included by Villani in the earliest catalogue given by him of the great Florentine houses. Cacciaguida, one of the Elisei, born in 1106, married a daughter of the Aldighieri, a family of Ferrara. Their son was christened Aldighiero, and this was adopted by the family as a surname, afterwards changed to Alighieri. The son of Aldighiero was Bellincione, father of Aldighiero II., the father of Dante.