Waleran de Beaumont — was an Anglo-Norman nobleman. In his early adulthood, he was a member of the conspiracy of Amaury III of Montfort ; later in his career, he participated in the Anarchy and the Second Crusade. They remained in his care till late in when they were declared adult and allowed to succeed to their father's lands by a division already arranged between the king and their father before his death. By the arrangement, Waleran succeeded to the county of Meulan upriver on the Seine from the Norman border, and the principal family Norman honors of Beaumont-le-Roger and Pont Audemer.
His great possessions included the forest of Brotonne, which was centred on his castle of Vatteville on the left bank of the Seine. As part of the family arrangement, Waleran also received a large estate in Dorset centred on the manor of Sturminster Marshall.
The king, however, detected the conspiracy, and Waleran and his young colleagues were caught unawares by a preemptive strike by the king's army against the rebel centre of Montfort-sur-Risle. Waleran rallied and based his resistance to the king at his castle of Brionne. In October , he lost his fortress of Pont Audemer on the Norman coast to a siege, despite calling in military help from his French relations and allies. Waleran's remaining castles continued to resist until 16 April when Waleran was forced by the king to order his seneschal Morin du Pin to surrender them.
Waleran's lands were seized and he was imprisoned first at Rouen, then at Bridgnorth in Shropshire and finally at Wallingford Castle. Waleran was released for unknown reasons in He resumed an active role at court and he and his twin brother were both present at Henry's deathbed. He was probably involved in the discussions of the Norman magnates in December as to who should succeed to Normandy and England. The accession of Stephen may have taken him by surprise but he had already offered his allegiance to the new king before Easter At the court he was betrothed to the king's infant daughter, Matilda, and received the city and county of Worcester as her marriage portion.
After Easter he went to Normandy taking authority from the king to act as his lieutenant in the duchy. In September he commanded the army of Norman magnates which repelled the invasion by Geoffrey of Anjou , husband of the Empress Matilda , daughter of Henry I.
