This friendship was soon put to the proof. The party which had been defeated on the departure of the Duke of Calabria from Siena could not forget the mortification. In the beginning of April 1485, the Sienese ambassador at Florence announced that a body of 2,000 men, under the command of Giulio Orsini, was meditating an attack; whereupon a considerable force under Ranuccio da Farnese was despatched to the threatened ally.[272] It was believed that Perugia, Spoleto, and Todi served as places of meeting for the discontented, and that the Cardinal della Rovere had a hand in the undertaking. On May 4, Lorenzo wrote from Bagno a Morba to Siena[273] that they must look to the security of the frontiers. It was said that the Pope was inclined to maintain peace, and had spoken to the ambassadors to that effect. By the Florentines he had been urged to give practical proof of his good intentions, and not to suffer his dominions to be a harbour for designs against neighbouring States. ‘Your Lordships must know,’ he continues, ‘better than I who am at a distance, what is your internal state and the mind of the citizens. If you are united, then, in my opinion, you have nothing to fear: for Siena is not to be taken with 2,000 men, and if the number of the aggressors increases, you will also receive increased assistance. Of that you need not doubt. Therefore, if there is among your citizens the amount of concord and love which is reckoned upon, your affairs will take a favourable course. I do not believe that this movement of the exiles can count on much support; for we hear from Lombardy that all the chief powers are desirous of peace. Nevertheless it is your and our duty to prepare for the worst and to have all available means in readiness. Thereunto I desire to encourage your Lordships, assuring you that we are of one mind with you, as events will prove.’