The successor of Sixtus was Cardinal Cibò, who took the title of Innocent VIII. Between him and Duke Federigo had existed an old friendship, which was cordially extended to Guidobaldo, and also to Ottaviano Ubaldini: to these, therefore, it was a pleasure as well as a duty to lay their congratulations at his feet, in return for which a new investiture, already prepared by order of the late Pontiff, was promptly forwarded to the young Duke. The aggressions of the Turk, that standing grievance of Christian Europe, had of late menaced Italy itself, and each pope, on ascending the chair of St. Peter, sought to signalise his zeal by uniting the Peninsular powers against the common foe. Yet, like his predecessors, Innocent was quickly diverted from a project vast, glorious, and attractive, but impracticable, to meaner objects; from the cause of Christianity to ebullitions of personal pique. The rigour with which he exacted from the King of Naples some arrears of _cense_, or ecclesiastical tribute, due to the Camera under old investitures, but which had been modified by Sixtus IV., occasioned an exchange of harsh words. There occurred at Aquila, about the same time, a most serious insurrection, headed by some Neapolitan nobles belonging to the Angevine party, who, exasperated by a long course of oppressive and injudicious government, appealed to Innocent for assistance. The occasion seemed tempting for gratifying his indignation against Ferdinand I., and for adding to the papal states that important fief. The grand crusade against the Crescent was once more forgotten, and the Pope, entering upon the career of Sixtus, became the perturbator in place of the pacificator of unhappy Italy. Among other small princes whom he retained for this struggle was Guidobaldo, nor did he omit to secure the Venetians. Ferdinand was not idle on his side, having made an alliance with the Florentines. Whilst the ecclesiastical troops, under Roberto da Sanseverino and the Prefect della Rovere, seconding the rebellious barons of Naples, carried an aggressive war into the Abruzzi, the King made a diversion in La Marca, by means of some military adventurers, who, at his instigation, stirred up the people of Città di Castello, Fano, and Osimo, to throw off the papal sway. To quell these movements, the troops of Urbino, led by commanders sent by Innocent, and still more the influence of the Duke, proved highly instrumental. The war, begun without just cause, and leading to no important result, ended, as usual, in a league which left the parties much as before. It included the Pope, the King, Giovanni Galeazzo Sforza, and the Venetian Republic, and was hailed with a joy that seemed wilfully oblivious of the hollowness of former pacifications. It was concluded on the 11th of August, 1485, and, unlike these, it secured the quiet of Italy during the remainder of that pontificate.