Louis XII. having established a league comprising Florence, Siena, Lucca, and Bologna, Pandolfo Petrucci, escorted by a French troop, returned to Siena, March 29, 1503. Discord, however, arose among the allies and gave Caesar renewed hope. The dominion of the Pope and his son Caesar did not extend beyond the Patrimonium Petri and even there it was limited by Ferrara and Bologna. Valentino, profiting by conditions in the Regno, began to plot with Spain, who saw in him an able ally against France. In April, 1503, Gonsalvo de Cordova had begun a brilliant campaign in Apulia; the French commanders Aubigny and Nemours were repeatedly defeated and finally Gonsalvo entered Naples, May 14th, the remnant of the French forces retreating to Gaeta. Louis XII. sent all the troops he had at Genoa, under the command of the Marquis of Saluzzo, to aid the beleaguered army in Gaeta and in the meantime Gonsalvo had decided to attempt the capture of the place and also of Castel Nuovo, the last strongholds of the French. The latter place surrendered, but the former held out until the arrival of the Marquis of Saluzzo, who forced the Spaniards to retreat to Naples. In the meantime Prospero Colonna, who was in the service of Spain, had been uniformly successful in Calabria and the Abruzzi. Caesar and the Pope anxiously followed the course of events in the south; the defeat of France would permit them to renew their efforts against Siena and Perugia, and also against Giangiordano Orsini. Valentino could accept the lordship of Siena, which the inhabitants had offered him but which Louis, out of regard for Florence, had compelled him to refuse, and once in possession of Pisa he could attack Florence. Caesar had been forced to defer his own projects in Romagna because of the sending of forces from Genoa by Louis to aid the besieged at Gaeta. By his agreement he was required to assist the King of France, and he had already dispatched some of his captains--among them Fracasso and the Count of Mirandola--to the French camp, and by the middle of July he had gathered a considerable force about Perugia. The rumours that the Pope and Caesar were plotting with Spain continued, and the tyrants whom they had been endeavouring to crush asked permission of the King of France to proceed against the Duke. Above all, Guidobaldo di Montefeltre hoped his relative, the Marquis of Mantua, would help him to return to Urbino.