The Florentine Franzesi family was of recent nobility. Musciatto's father was a knight and had been a supporter of the Empire. It is not known when or under what circumstances Musciatto and his brother Albizzi moved to France. By 1290, the Franzesi brothers became bankers for Phillip IV, King of France.

Franzesi's position of influence within the French court gained him many exemptions and special privileges not accorded to other Italians in French territory. It also alienated him quite decidedly from his Italian compatriots, who, feeling resentment and hostility, painted him as a traitor to Italian economic interests. The chronicler Giovanni Villani reiterates the prevalent accusation (for which there is no concrete evidence) that Musciatto had been the inspiration behind Phillip IV's order to arrest all the Italian merchants and bankers on French soil and confiscate their assets.

In the 1290's, the prosperous Franzesi brothers gained many clients, including Charles II of Naples and Pope Boniface VIII. Musciatto profited from the French-English hostilities by financing French war expenses. He served brilliantly in important diplomatic and military assignments for France. The firm was transferred to Siena at the end of the century. Musciatto's adherence to the Black Guelph faction, predominant after 1301, elevated him to a number of political and military appointments. His fortune, however, took a downturn in 1305, when he faced a sudden bankruptcy and an accusation of theft of papal treasure. He died, with no heirs, before July 1307.

In the opening tale of the Decameron (I.1), the hypocritical ser Cepperello is cast as an agent of Musciatto, entrusted with collecting the accounts of some of Musciatto's most difficult clients. It appears that there is, in fact, historical documentation which proves a relationship between Musciatto and a "Cepperello" or "Ciapperello Dietaiuti". In any case, the mere name of Musciatto was enough to guarantee ser Cepperello's negative credentials.

(R.P./N.S.) Astorri, Antonella. s.v. Franzesi, Giovanni Paolo. Vol. 50. Dizionario biografico degli italiani, Roma: Istituto della Enciclopedia italiana, 1960. pp. 262-264.