[2] However, the Duchy of Athens, except for Argos and Nauplia, had been overrun by the Catalan Company, and Walter spent much of his life in an unsuccessful struggle to recover that inheritance of his family.

To strengthen his position, Walter engaged in a strategic marriage to Beatrice, the niece of King Robert of Naples and daughter of Philip I of Taranto by Thamar Angelina Komnene, in December 1325.

Walter VI's almost-princely position in the Angevin court soon won him an appointment as Vicar for Charles of Calabria, an office that he only exercised for a few months in 1325.

After 1321, Walter repeatedly announced his intention to campaign in Greece and recover the Duchy of Athens, but financial constraints and his obligations to the King of Naples kept him occupied in Italy.

Sailing from Brindisi in August, Walter attacked first the Latin County palatine of Cephalonia and Zakynthos, and the Greek Despotate of Epirus, forcing them to recognize the overlordship of King Robert.

Walter had neither the troops to overwhelm the Catalans nor the money to sustain a prolonged war of sieges and attrition, and found no support among the native Greek population.

The Florentine nobility looked to foreign powers to solve the city's seemingly impossible financial problems, and found an ally in Walter of Brienne.

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.