The establishment of Francesco Sforza as Duke of Milan had virtually settled the affairs of Lombardy, for although the Emperor and the French King refused to recognise his rights to the Visconti succession, they deferred their respective claims upon that duchy till a fitter season. The Angevine pretensions to the crown of Naples were also in temporary abeyance, and the triple tiara had passed from the turbulent Eugenius to Nicholas V., whose early habits of scholarship continued undisturbed by ambitious dreams. There thus seemed no element of contention left, and a prolonged peace was the natural as well as the true policy of Italy. But, in the words of Sanzi, "No long repose Ausonia e'er can brook, For peace to her brings languor, and she deems It loathsome to lie fallow." So paltry were the pretexts, so remote the motives for renewed hostilities, that Sismondi is content to ascribe these to diplomatic intrigue, seconded by a general irritability of temperaments, and avows that, ere they were resumed, a review of interests and reconstruction of alliances became absolutely necessary. Venice and Florence had hitherto co-operated to protect themselves, and maintain a balance against the ambitious dynasties of Visconti and Aragon; but jealousy of the terra-firma acquisitions of the former having induced her sister republic to league with Sforza, she consulted at once her safety and her vengeance by an intimate union with Alfonso. Sigismondo Malatesta being retained in her service, the Duke of Milan bought him over by an offer of better terms, and the Count of Urbino, finding himself thus exposed to the same contact with his personal enemy which had recently annoyed him in the Maremma campaign, renounced his engagement with Sforza, and as a natural consequence transferred it to the other side. The King of Naples, disgusted by the late treachery of Sigismondo, and by similar instances of light faith on the part of other Italian condottieri, had announced his determination to employ none of them without sureties for their fidelity. But he made an exception in favour of Federigo, declining his offer of the Venetian signory as his sponsors, on the ground that he knew his word to be sufficient guarantee. In consequence, however, of the coronation of Frederick III. at Rome, and his stay in Italy, it was not until 1452 that these arrangements were so far completed as to enable the Venetians to declare war upon Sforza in May of that year, and Alfonso to publish hostilities with Florence in the following month.[90] [Footnote 90: Berni dates the Tuscan campaign as in 1451, but Sismondi is correct.]