Walter was the eldest son of
Guy Brisebarre,
lord of Beirut. A 1164 charter mentions Marie, lady of Beirut; the historian
Hans E. Mayer concludes that she was most likely Walter's mother, although he also had a sister with the same name. Walter succeeded his father as lord of Beirut in 1156 or 1157. Beirut was one of the greatest
fiefs of the kingdom, owing 21
knights to the crown, and the
lord of Toron,
Toron II, held the
lordship of Banias in fief from the lord of Beirut. Walter's rule began with the
devastating 1157 earthquake; historian Mary E. Nickerson notes that "changes and catastrophes appear almost normal to him during the rest of his life". In October, he and his brothers,
Guy and Bernard, authorized Humphrey to grant a half of the lordship of Banias to the
Knights Hospitaller. Like his father before him, Walter was almost constantly in attendance to
King Baldwin III. In 1161 he witnessed the agreement by which the king granted the
lordship of Transjordan to the magnate
Philip of Milly in return for Philip's land in
Nablus. Walter was married to
Helena of Milly, the elder daughter of Philip. Philip outlived his only son, Rainier, some time after 1161. When in late 1165 he resigned his lordship to join the
Knights Templar, his only surviving children were two daughters, Helena and
Stephanie. According to the contemporary custom, Helena and Walter stood to inherit from her father the entire lordship of Transjordan. Transjordan, which owed 40 knights, was an even greater fief than Beirut. King Baldwin III died in Beirut in 1163. His brother and successor,
King Amalric, had to overcome opposition from his barons, and the Brisebarres did not attend him as frequently as they had Baldwin. In 1164, while King Amalric was conducting one of
his campaigns in Egypt, the Damascene ruler
Nur ad-Din Zengi captured numerous noblemen at the
Battle of Harim in 1164. The Brisebarre brothers–Walter, Guy and Bernard–were among the prisoners. Their mother apparently took charge of Beirut. According to the ''
Lignages d'Outremer'' from the late 13th century, they could not afford ransom because they were spendthrifts. Their mother was not able to raise enough money, so she offered to take their place as a hostage until the debt had been paid. King Amalric prohibited his subjects from lending money to the Brisebarres after their release. This forced them to accept the king's offer to pay the ransom in return for their exchange of Beirut for the much smaller fief of Blanchegarde. Walter's mother was then freed, but died only a month later. 12th-century charters, however, show that Walter exchanged Beirut not for Blanchegarde but for a
money fief in the vicinity of the city of
Acre. The historian Bernard Hamilton infers that King Amalric wished to prevent the union of two great lordships, Beirut and Transjordan, under Walter's rule. By 1167, Beirut was in the royal domain. ==Lordship of Transjordan==