Many words were not requisite to induce the duke to hostilities against the Florentines, for he was incited to it by hereditary hatred and blind ambition, and still more, by the fresh injuries which the league with the Genoese involved; yet his past expenses, the dangerous measures necessary, the remembrance of his recent losses, and the vain hopes of the exiles, alarmed him. As soon as he had learned the revolt of Genoa, he ordered Niccolo Piccinino to proceed thither with all his cavalry and whatever infantry he could raise, for the purpose of recovering her, before the citizens had time to become settled and establish a government; for he trusted greatly in the fortress within the city, which was held for him. And although Niccolo drove the Genoese from the mountains, took from them the valley of Pozeveri, where they had entrenched themselves, and obliged them to seek refuge within the walls of the city, he still found such an insurmountable obstacle in the resolute defense of the citizens, that he was compelled to withdraw. On this, at the suggestion of the Florentine exiles, he commanded Niccolo to attack them on the eastern side, upon the confines of Pisa in the Genoese territory, and to push the war with his utmost vigor, thinking this plan would manifest and develop the course best to be adopted. Niccolo therefore besieged and took Serezana, and having committed great ravages, by way of further alarming the Florentines he proceeded to Lucca, spreading a report that it was his intention to go to Naples to render assistance to the king of Aragon. Upon these new events Pope Eugenius left Florence and proceeded to Bologna, where he endeavored to effect an amicable arrangement between the league and the duke, intimating to the latter, that if he would not consent to some treaty, the pontiff must send Francesco Sforza to assist the league, for the latter was now his confederate, and served in his pay. Although the pope greatly exerted himself in this affair, his endeavors were unavailing; for the duke would not listen to any proposal that did not leave him the possession of Genoa, and the league had resolved that she should remain free; and, therefore, each party, having no other resource, prepared to continue the war.