De Verdun (de Verdon), Bertram (d. 1192), administrator, was the son of Norman de Verdon and his wife Lecelina, daughter of Geoffrey de Clinton. He rose to prominence as a dedicated servant of Henry II (qv) and was sheriff of Warwickshire and Leicestershire between 1168 and 1183; from 1175 to 1179 he acted as a regular justice in the curia regis and in the same period was also an itinerant justice. In October 1171 he possibly accompanied Henry II to Ireland and formed part of the king's impressive entourage; as sheriff of Warwickshire and Leicestershire he was central in organising supplies and victuals for the expedition. He remained loyal to Henry II in 1173 during the rebellion of the king's sons. Following the grant of the lordship of Ireland to the king's son John (qv), Bertram was appointed John's seneschal of Ireland and acted in that capacity 1184–6. In April 1185 he accompanied John on his notorious visit to Ireland, a visit roundly criticised by Gerald of Wales (qv) for its fecklessness and the numerous diplomatic blunders committed by John and his callow retinue. However, Gerald's account needs to be treated carefully, and Bertram was an able administrator, unlikely to give full rein to the inexperienced lord of Ireland and his dissolute followers. De Verdun appears to have remained in Ireland till 1189, and it was probably that year, shortly before he left the lordship, that he was granted extensive lands in Louth and south Armagh by John; previously he had been made custodian of the bridge and castle at Drogheda. Thereafter he seems to have delegated responsibility for his Irish estates to his sons Thomas and Nicholas, though he is credited with the foundation of Dundalk town and may have been responsible for the creation of the Hospital of St Leonard at Dundalk for the Fratres Cruciferi. He accompanied Richard I on crusade in 1190 and was one of the guarantors for Richard in the king's treaty with Tancred of Sicily in November that year. When Richard began his unsuccessful march on Jerusalem, Bertram was initially left in charge of the king's household at Acre, although sometime afterwards he seems to have rejoined Richard's forces. He died at the battle of Jaffa on 6 (?) August 1192.
His first marriage to Maud, daughter of Robert Ferrers, earl of Derby, produced no children. With his second wife, Rohese (or Rohais), he had several sons and a daughter, Lecelina, who became the wife of Hugh de Lacy (qv), earl of Ulster.