The kingdom of Naples, on the death of Alfonso the Magnanimous in 1458, had been separated from Sicily, and passed by testamentary appointment to his natural son Ferdinand.  The bastard Aragonese dynasty was Italian in its tastes and interests, though unpopular both with the barons of the realm and with the people, who in their restlessness were ready to welcome any foreign deliverer from its oppressive yoke.  This state of general discontent rendered the revival of the old Angevine party, and their resort to French aid, a source of peril to the monarchy.  It also served as a convenient fulcrum for the ambitious schemes of conquest which the princes of the House of Aragon in Spain began to entertain.  In territorial extent the kingdom of Naples was the most considerable parcel of the Italian community.  It embraced the whole of Calabria, Apulia, the Abruzzi, and the Terra di Lavoro; marching on its northern boundary with the Papal States, and having no other neighbors.  But though so large and so compact a State, the semifeudal system of government which had obtained in Naples since the first conquest of the country by the Normans, the nature of its population, and the savage dynastic wars to which it had been constantly exposed, rendered it more backward in civilization than the northern and central provinces.

The Papacy, after the ending of the schism and the settlement of Nicholas V. at Rome in 1447, gradually tended to become an Italian sovereignty.  During the residence of the Popes at Avignon, and the weakness of the Papal See which followed in the period of the Councils (Pisa, Constance, and Basel), it had lost its hold not only on the immediate neighborhood of Rome, but also on its outlying possessions in Umbria, the Marches of Ancona, and the Exarchate of Ravenna.  The great Houses of Colonna and Orsini asserted independence in their principalities.  Bologna and Perugia pretended to republican government under the shadow of noble families; Bentivogli, Bracci, Baglioni.  Imola, Faenza, Forli, Rimini, Pesaro, Urbino, Camerino, Citta di Castello, obeyed the rule of tyrants, who were practically lords of these cities though they bore the titles of Papal vicars, and who maintained themselves in wealth and power by exercising the profession of condottieri.  It was the chief object of the Popes, after they were freed from the pressing perils of General Councils, and were once more settled in their capital and recognized as sovereigns by the European Powers, to subdue their vassals and consolidate their provinces into a homogeneous kingdom.  This plan was conceived and carried out by a succession of vigorous and unscrupulous Pontiffs—­Sixtus IV., Alexander VI., Julius II., and Leo X.—­throughout the period of distracting foreign wars which agitated Italy.  They followed for the most part one line of policy, which was to place the wealth and authority of the Holy See at the disposal of their relatives, Riarios, Delia Roveres, Borgias, and Medici.