This article presents the critical editions of two texts: a letter by the Duke of Milan Filippo Maria Visconti (but written on his behalf by Pier Candido Decembrio) sent to Poggio Bracciolini on 28 July 1438; and the response written by Poggio on 15 September. Poggio’s letter contains a brief treatise in praise of Florence and of the Florentina libertas. The documents illuminate a crucial epi…