Background
His father Hamelin granted him the manor of Appleby, North Lincolnshire.
lieutenant of Gascony Lord Warden
His father Hamelin granted him the manor of Appleby, North Lincolnshire.
De Warenne was present at the coronation of John, King of England on 27 May 1199. When Normandy was lost to the French in 1204 he lost his Norman holdings, (in 1202 he was lieutenant of Gascony), but John recompensed him with Grantham and Stamford. His first tenure of office as Lord Warden of the Cinque Ports began in 1204, and lasted until 1206.
He was also a Warden of the Welsh Marches between 1208 and 1213.
His allegiance only faltered a few times when the king’s cause looked hopeless. In March 1217 he again demonstrated his loyalty to England by supporting the young King Henry III, and he was also responsible for the establishment of Salisbury Cathedral.
Between the years 1200 and 1208, and during 1217–1226 he was to serve as the High Sheriff of Surrey. In 1214 he was again appointed Lord Warden of the Cinque Ports.
William married Maud Marshal, on 13 October 1225.
The son John (1231–1304) succeeded his father as earl, while the daughter, Isabel de Warenne (c 1228–1282), married Hugh d"Aubigny, 5th Earl of Arundel. William may also have had an earlier, childless marriage to another Matilda, daughter of William d"Aubigny, 2nd Earl of Arundel.