de Mara acting as his deputy (List of Sheriffs, p. 135). In March 1220 he excused his attendance at Henry III's coronation on the plea of a severe illness (Fœdera, i. 160). At Whitsuntide 1220 he was ordered to escort Alexander, king of Scots, from Berwick to York (Rot. Lit. Claus. p. 436). On the fall of Falkes de Breauté in 1224, Warenne received the custody of his wife (Rog. Wend. iv. 99); and after the order for Falkes's banishment was issued, Warenne conducted him to his ship (ib. iv. 103; see Breauté, Falkes de). On 11 Feb. 1225 he witnessed the confirmation of Magna Carta and the issue of the charter of the forest (Burton Annals, pp. 232, 236). On 11 July 1226 he was among those of the king's council urged by the pope to labour for the reconciliation of Falkes de Breauté (Cal. Papal Letters, 1198–1304, p. 112). In 1227 Warenne joined Richard, earl of Cornwall [q. v.], when that noble quarrelled with his brother, Henry III. A great meeting of Richard's party was held at Warenne's town of Stamford (ib. iv. 143). In May 1230, when Henry III went abroad, Warenne was one of the three justices who acted as regents during his absence (Tewkesbury Annals, p. 74). He was friendly with the justiciar, Hubert de Burgh, and several letters between them are printed in Shirley's ‘Royal Letters’ (i. 15, 42, 112, &c.). In June 1230 he was appointed to carry out the assize of arms in Surrey and Sussex (Royal Letters, i. 373). When Hubert de Burgh fell in 1232, Warenne joined with Richard of Cornwall and the Earls Marshal and Ferrars in acting as sureties for the disgraced justiciar, who was confined at Devizes Castle under the charge of four knights of the above four earls (Rog. Wend. iv. 258; Tewkesbury Annals, p. 88; Royal Letters, i. 410). He witnessed the reissue of the charter on 28 Jan. 1236 (Tewkesbury Annals, p. 104). In January 1236 he acted as chief butler at the coronation of Queen Eleanor, in place of his son-in-law, Hugh de Albini, earl of Arundel or Sussex, a minor (Matt. Paris, iii. 338), and in 1237 was one of the opposition leaders who were made members of the royal council (ib. iii. 383). In 1238 he was sent by the king to Oxford with an armed force to save the legate Otho and his followers from the violence of the Oxford scholars. He imprisoned Odo of Kilkenny and three other masters in Wallingford Castle (ib. iii. 483–4). He was one of the four barons made treasurers of the thirtieth without whose approval the king could not spend it (Matt. Paris, iv. 186). He died on 27 May 1240 at London (ib. iv. 12), and was buried at Lewes priory.
Warenne was the founder of a small priory of Austin canons at Reigate (Monasticon, vi. 517–18). He confirmed old and made new grants to Lewes priory, and made grants to Roche Abbey, Yorkshire. Watson summarises most of these and other benefactions. He had serious difficulties in his dealings with Lewes priory and the abbot of Cluny, its alien chief (Cal. Papal Letters, 1198–1304, pp. 119, 186). In 1238 Warenne was cited before Bishop Grosseteste for permitting mass to be celebrated indecorously in the hall of his manor at Grantham (Grosseteste, Epistolæ, pp. 171–3, Rolls Ser.). He was no friend of the Jews, arresting some of his Jewish burgesses at Grantham in 1222 on the charge of making a game in ridicule of the Christian faith. However, he released them under bail (Rot. Lit. Claus. p. 491).
Warenne is said to have married, as his first wife, Matilda, daughter of William of Albini, earl of Sussex, who died in 1215 without issue, and was buried at Lewes (Dugdale, i. 77; Watson, i. 208). If so, she may have been the Countess of Warenne who was imprisoned in 1203 and found sureties, one of whom was William of Albini (Rot. Lit. Pat. p. 29). Otherwise it was William's aged mother. He certainly married in 1225 Matilda, the eldest daughter and subsequently coheiress of William Marshal, earl of Pembroke (d. 1219) [q. v.] Matilda was the widow of Hugh Bigod, third earl of Norfolk, who died in February 1225. She married her second husband ‘immediately’ (Dunstable Annals, p. 94), certainly by October 1225. By her Warenne was the father of John de Warenne (1231?–1304) [q. v.], his successor. Their daughter Isabella married Hugh de Albini, earl of Sussex, who died in 1243. Isabella survived him nearly forty years. It was not until after her death in 1282 that her brother, John de Warenne, began to be styled Earl of Sussex as well as of Surrey. William's more usual title was ‘Comes de Warenne.’ Watson, though not apparently on good authority, assigns to William an illegitimate son, Griffin de Warenne, and a daughter, who was King John's mistress and the mother of Richard, the king's son, who killed Eustace the Monk.
[Rotuli Literarum Clausarum, Rotuli Literarum Patentium, Rotuli Cartarum, Rymer's Fœdera, vol. i. (all in Record Comm.); Calendar of Papal Letters, 1198–1304; Stubbs's Select Charters; Roger of Wendover (Engl. Hist. Soc.); Gervase of Canterbury, Ralph Coggeshall, Matthew Paris's Chron. Majora, Tewkesbury and Dunstaple Annals, in Annales Monastici (all in Rolls Ser.); Dugdale's Baronage, i. 76–7;