His first mission was in 1499 to Catherina Sforza, “my lady of Forli” of The Prince , from whose conduct and fate he drew the moral that it is far better to earn the confidence of the people than to rely on fortresses. This is a very noticeable principle in Machiavelli, and is urged by him in many ways as a matter of vital importance to princes.

In 1500 he was sent to France to obtain terms from Louis XII for continuing the war against Pisa: this king it was who, in his conduct of affairs in Italy, committed the five capital errors in statecraft summarized in The Prince , and was consequently driven out. He, also, it was who made the dissolution of his marriage a condition of support to Pope Alexander VI ; which leads Machiavelli to refer those who urge that such promises should be kept to what he has written concerning the faith of princes.