25 they had a taste of this mistake; for, having found him a most valiant man (they beat the Duke of Milan under his leadership), and, on the other hand, knowing how lukewarm he was in the war, they feared they would no longer conquer under him, and for this reason they were not willing, nor were they able, to let him go; and so, not to lose again that which they had acquired, they were compelled, in order to secure themselves, to murder him. They had afterwards for their captains Bartolomeo da Bergamo, Roberto da San Severino, the count of Pitigliano, 26 and the like, under whom they had to dread loss and not gain, as happened afterwards at Vaila, 27 where in one battle they lost that which in eight hundred years they had acquired with so much trouble. Because from such arms conquests come but slowly, long delayed and inconsiderable, but the losses sudden and portentous.