6 The "old duke" is Guidobaldo da Montefeltro ( 1482-1508). Machiavelli is not quite correct here, when he says that the San Leo's revolt was a censequence of the Diet of La Magione. In fact the rebellion of San Leo against Duke Valentino took place on October 5, 1502, a few days before the conclusion of the Diet of La Magione on October 9, 1502. In the Legation, letter of October 7, 1502, these facts are narrated differetly and more accurately by Machiavelli.