Walter VI of Brienne (c. 1304 – 19 September 1356) was a French nobleman and crusader. He was the count of Brienne in France, the count of Conversano and Lecce in southern Italy and claimant to the Duchy of Athens in Frankish Greece. Life Early life in Italy Walter was the son of Count Walter V of Brienne, duke of Athens, and Jeanne de Châtillon (died 1354), the daughter of the count of Porcien, constable to King Philip IV of France. As grandson of Count Hugh of Brienne (d. 1296), he was heir to a vast property all around the Mediterranean. After his father's death at the Battle of Halmyros on 15 March 1311, Walter became count of Brienne, Lecce, and Conversano. 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. He spent most of his life in Italy and France and left Argos-Nauplia to be ruled by guardians. His mother Jeanne carried out a vigorous struggle against the Catalans during his minority, which, however, had little military effect but impoverished him. 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. At this time, Florence requested King Robert's support in protecting Guelph interests in Italy, and elected his son, Charles, Duke 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 that he only exercised for a few months in 1325. Anti-Catalan crusade of 1331–1332 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. In 1328, he even briefly concluded a truce with the Catalans. Thus it was not until 1330 that a serious effort got under way. In June 1330, Pope John XXII issued a crusading bull for Walter, and ordered prelates in Italy and Greece to preach for a crusade against the Catalans; shortly after, King Robert of Naples also gave the crusade his support, and allowed his feudatories to join it.