especially of his mother, who was then labouring under the evils of old age and sickness.[147] About this time Martin had an opportunity of gratifying the animosity which he entertained against the Florentines, by secretly fomenting certain disputes which had taken place between the administrators of their republic and the duke of Milan. Encouraged by the connivance of the pontiff, that prince declared war against the Tuscan state, the territories of which he menaced with a considerable army. In the course of this contest, which was singularly obstinate and bloody, the pontiff had the satisfaction of retaining in his own hands the balance of power; and of beholding the supercilious Tuscans, humbled by disasters and defeats, suing to him for assistance, and entreating his mediation for the restoration of peace. Martin, though he professed the strictest impartiality between the hostile parties, not only refused to assist the Florentines, but still continued secretly to stimulate the ambition of their adversary. Being thus disappointed in their application to the pontiff, the Florentines had recourse to the Venetians, whose dread of the growing power of the duke of Milan induced them readily to enter into an alliance with his antagonists. Animated by this accession of strength, the Florentines prosecuted the war with renewed vigour, and with such success, that the duke was glad to accept of the mediation opportunely proffered by his friend the pontiff, under whose auspices a peace was concluded at Ferrara in the year 1428.[148]