His father Hamelin granted him the manor of Appleby, North Lincolnshire.
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 Welch marches between 1208-1213.
William was one of the few barons who remained loyal to King John (who was his cousin) during the king's difficulties with the barons, when they sought for the French prince to assume the English throne, and is listed as one of those who advised John to accede to the Magna Carta. 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, he was also responsible for the establishment of the cathedral at Salisbury.
Between the years 1200-1208, and during 1213-1226 he was to serve as the Sheriff of Wiltshire. In 1214 he was again appointed Lord Warden of the Cinque Ports.
|Offspring of William de Warenne and Maud Marshal (1192-1248)|
|John de Warenne (1231-1304)||1231||29 September 1304|| Alice de Lusignan (1224-1256)|
|Isabel de Warenne (c1228-1282)||1228||1282|| Hugh of Aubigny (c1215-1243)|
|Offspring of Hamelin de Warenne and Isabel de Warenne (1130-1202)|
|William de Warenne (1166-1240)||1166||1240|| Maud Marshal (1192-1248)|
|Adela de Warenne (c1170-c1218)||1170||1218|| John of England (1167-1216)|
|Isabel de Warenne (?-1234)|| |
|Maud de Warenne (c1162-c1212)||1162||1212|| Henri Hastings (-c1183)|
- wikipedia:en:William de Warenne, 5th Earl of Surrey - Wikipedia
- William Warren
- Warren in Cheshire
- Warenne Family Ancestry
- Royal Title Ancestors #4040
- Memoirs of the Earls of Warren and Surrey - by Watson, first published in 1782 and recently reproduced on CD rom.. This has further details together with family trees that can be found therein.
- A History and genealogy of the Warren Family - by Rev. Thomas Warren, first published in 1902. This has been reprinted on several occasions.
- Ancestral Roots of Certain American Colonists Who Came to America Before 1700 by Frederick Lewis Weis, Lines: 83-28, 153A-20, 153A-29, 161-27.
Common ancestors of William de Warenne (1166-1240) and Maud Marshal (1192-1248)
- Adelaide de Vermandois (1064-1120)
- Elizabeth de Vermandois (c1081-1131)
- Hugh de Vermandois (1053-1101)
Namesakes of William de Warenne (1166-1240)