The "Duke of Athens," as Walter VI was known to the Italians who experienced his ill-fated signoria in Florence, was, in fact, descended from French nobility. His mother, Giovanna de Chatillon, was the daughter of a constable to King Philip IV; his father, Walter V, held the titles of Count of Brienne and Lecce, and Duke of Athens. Walter's father fought unsuccessfully to defend his claim to Athens after its occupation by Catalan mercenaries in 1311. Despite a life-long dedication to this cause, Walter VI was never able to reclaim his Dukedom.
Walter VI of Brienne engaged in a strategic marriage to Margaret, the niece of Naples' King Robert, in 1321. At this time, Florence requested King Robert's support in protecting Guelph interests in Italy, and elected his son, Charles of Calabria, as signore of Florence for a ten-year period (1326-36). Walter VI's almost-princely position in the Angevin court soon won him an appointment as Vicar for Charles of Calabria, an office which he only exercised for a few months in 1326.
Walter VI spent the years following his brief appointment in Florence futilely attempting to recover Athens from the Catalans. However, he returned to Italy in 1342 when the Florentine ruling class of wealthy merchants called upon him to rule the city. Since 1339, Florence had been in the grip of a severe economic crisis brought about by immense English debts to Florentine banking houses, and by astronomical public debts incurred in trying to obtain the nearby city of Lucca from its Veronese lord, Mastino della Scala. The Florentine nobility looked to foreign powers to solve the city's seemingly impossible financial problems, and found an ally in Walter of Brienne. Although the ruling class invited Walter to rule for a limited time, the lower classes, who were fed up with the ineptitude of Walter's predecessors, unexpectedly proclaimed him signore for life.
Walter VI ruled despotically, ignoring or directly opposing the interests of the very same merchant class which had brought him to power. The "Duke of Athens" imposed harsh economic correctives on the Florentines, including the flat tax estimo, and prestanze, postponements of the city's repayment of loans forced from the wealthier citizens. These measures both angered the Florentines, and did help alleviate the crisis that had been stewing for years. After only ten months, Walter of Brienne's signoria was cut short by conspiracy. Walter VI was not only forced to resign from office, but barely escaped Florence with his life.
The "Duke of Athens" who appears in the seventh tale of Day Two of the Decameron as one of the nine lovers of the Sultan of Babylon's daughter, while not historically accurate, is probably a sarcastic allusion to Walter VI - his brief, but unforgettable dictatorship in Florence occurred less than ten years before the writing of the Decameron.
(R.P./N.S.) Adapted from Ingeborg, Walter. s.v. Brienne, Gualtieri di. vol. 14. Dizionario biografico degli italiani, Roma: Istituto della Enciclopedia italiana, 1960. pp. 237-251; Schevill, Ferdinand. The History of Florence from the Founding of the City through the Renaissance, New York: Harcourt Brace, 1936. pp. 217-225.