THE Pazzi conspiracy was only a prelude to the events which caused a Neapolitan army to stand as an enemy before the walls of Rome. The Pope and the Venetians had had no time to give free course to their spite against old enemies or former allies so long as the storm was hanging over the Apulian coast. Sixtus IV. even showed himself friendly to the Florentines, and Guid’Antonio Vespucci, who, towards the end of January 1481, returned to Rome as ambassador, endeavoured to strengthen this good understanding. But no sooner had the imminent danger from the East disappeared than the object of clearing the coast of Albania and Western Greece of the Turks, which might have been more easily attained then than at any previous period, passed out of sight. A dispute between Venice and Ferrara furnished an occasion for fresh strife. Ercole of Este refused to recognise any longer as valid certain old and burdensome obligations which kept him in a sort of dependence on the Republic with respect to the execution of justice in his capital by a Venetian vicegerent, and the procuring of salt from Venetian saltworks. The dispute rose to such a height that Venice threatened to take up arms; she thought the moment favourable on account of her alliance with the Pope. Sixtus IV. had sound reasons for avoiding everything that could favour the interference of Venice in the affairs of Ferrara and Romagna; but the requirements of prudent policy were driven into the background by the selfish ambition of his nephew, who hoped to strengthen his position in Romagna by Venetian influence. Duke Ercole vainly tried through Cardinal Giuliano della Rovere to make the Pope understand that it would be neither to the honour nor the advantage of the Holy See to leave him to be crushed by the superior power of Venice.[233] Girolamo Riario went to Venice, where he was most honourably received and presented with the patriciate. War was decided on. King Ferrante sided with his son-in-law, as did also Milan and Florence. The alliance of Bologna and several of the lords of Romagna was secure; Siena and Genoa adhered to the Pope and Venice. Most of the captains of the Tuscan war undertook the leadership again, under somewhat altered circumstances. Besides Roberto Malatesta, the Venetians gained Roberto da Sanseverino, who had fallen out with Lodovico Sforza and given him a great deal of trouble in his own territory. The command of the Milanese troops was entrusted to the Duke of Urbino. The Florentines were led by Costanzo Sforza, to whom the general’s _bâton_ had been solemnly presented October 2, 1481.[234] In the spring of 1482 the struggle began in several quarters at once.[235]