A great French aristocratic family that provided rulers for the kingdom of Jerusalem, the Latin Empire of Constantinople, and the duchy of Athens.
The lords of Brienne were vassals of the counts of Champagne, holding lands near Troyes. The family had a long tradition of crusading. Erard I took the cross in 1097. His son Walter II took part in the Second Crusade (1147-1149), as did his son Erard II, who also joined the Third Crusade in 1189 and took part in the siege of Acre. Walter III originally agreed to go on the Fourth Crusade (1202-1204) in the army of the count of Champagne, but he was allowed to substitute service in southern Italy against Markward of Anweiler, a move that enabled him to press the claims of his wife, Elvira, to the county of Lecce and the principality of Taranto. His younger brother John was perhaps the most famous member of the family to involve himself in the crusading movement. He became king of Jerusalem in right of his wife, Maria (1210-1212), and regent of Jerusalem for his daughter Isabella II (1212-1225). Later he served as marshal of the papal armies in Italy opposed to his own son-in-law Frederick II, Holy Roman Emperor, and subsequently he became co-ruler of the Latin Empire of Constantinople (1230-1237) along with Emperor Baldwin II.
John’s nephew Walter IV, count of Brienne and Lecce (1205-1250), became count of Jaffa in 1221. Thereafter the family interests became centered in Frankish Greece. Hugh of Brienne (1250-1296) was influential at the Angevin court of Naples. He married first Isabella of La Roche (1277) and subsequently Helena Doukaina, the widow of his former brother-in-law, William of La Roche (1291), and thereby became bailli (regent) of the duchy of Athens for his stepson Guy. On the latter’s death in 1309, Hugh’s own son Walter V of Brienne became duke of Athens (as Walter I). He was killed at the battle of Halmyros against the Catalan Company in 1311 and was thus the last French duke of Athens. His son Walter VI was titular duke of Athens (as Walter II) until his death, fighting against the English as constable of France at Poitiers in 1356. In 1331-1332 he mounted a considerable campaign against the Catalans, but they refused to give battle. The cost effectively ruined the Brienne family. His only child, also called Walter, predeceased him in 1332
Battle of Halmyros, (1311)
A battle fought on 15 March 1311, between Walter I, duke of Athens, supported by many of the leading knights of Frankish Greece, and the Catalan Company, the duke’s former mercenaries, whom he was trying to dismiss from his service and remove from his duchy.
The battle was decisive in that many members of the French ruling element in central Greece were slaughtered and replaced by the victorious Catalans. Like other battles of the fourteenth century, it demonstrated how well-drilled foot soldiers with crossbow support could trounce an army of mounted knights. The site of the battle is not securely known. The medieval writers Ramon Muntaner and Nikephoros Gregoras both located the battle on the marshy plain of the Kephissos in the region of Orchomenos; in this they were followed by all writers before 1940, who thus named the engagement the battle of the Kephissos. In 1940 a hitherto unknown letter of Marino Sanudo came to light; written in 1327, it referred to the battle taking place near Halmyros, presumably at or near the modern town of Halmyros, just south of modern Volos on the Pagasaitic Gulf.