Isabella of Brienne (1306–1360) was suo jure Countess of Lecce and Conversano, claimant to the Duchy of Athens and Kingdom of Jerusalem, etc. Early life She was daughter of Walter V of Brienne, Duke of Athens, who was killed at the Battle of Halmyros near Thebes, Greece, in 1311. As the granddaughter of Hugh of Brienne, Count of Lecce etc., she was a descendant of the Kings of Jerusalem and of Cyprus. Her father's life was largely spent in Greece, where he tried to win back his mother's inheritance, the Duchy of Athens. Walter V of Brienne hired the Catalan Company, a group of mercenaries founded by Roger de Flor, to fight against the Byzantine successor states of Epirus and Nicaea, but when he tried to cheat and kill them in 1311, they slew him at the Battle of Halmyros and took over the Duchy, making Catalan the official language and replacing the French and Byzantine-derived laws of the Principality of Achaea with the laws of Catalonia, soon making it up as Duchy of Neopatras. When the duke Gauthier was killed, Isabella's mother Jeanne de Châtillon (died 1354), daughter of count of Porcien, may have tried to hold the Acropolis of Athens against the attacking Catalans, but eventually surrendered it. The Brienne family retainers continued to hold the Lordship of Argos and Nauplia under Walter of Foucherolles. Duchess Joanna however fled with her two young children to France, where the family had properties in Champagne, around Brienne-le-Chateau. The impoverished family was not able to provide better, and Isabella married a Walloon knight, Walter III of Enghien, whose lordships in and around the Hainaut were not unsubstantial (Condé, Enghien). Countess of Lecce and Brienne Her brother Walter VI of Brienne gradually gained better positions, and by allying with the Angevin kings of Naples, recovered some Italian fiefs. As constable of France, he was killed in the battle of Poitiers in 1356. He had also been Lord of Florence, Marshal of France, Count of Lecce, Conversano etc. He was an ally of the Angevins of Naples, and participated in their policies in Italy. His children died young, both with his first wife Margherita of Anjou-Tarent and his second, his distant kinswoman Jeanne de Brienne. His sister Isabella's children therefore succeeded to his possessions and claims. Already by 1350, Isabella's heir Sohier of Enghien resided in Greece and held Argos and Nauplia. Isabella