married in 1163 or 1164, and he was already of sufficient age to consent to and witness charters in the early part of the reign of Richard I (Hearne, Liber Niger Scaccarii, i. 371). He was therefore much over age when his father's death, in April 1202, put him in possession of both title and estates. His earlier acts are liable to be confused with those of William Warenne of Wormegay, justice of the Jews and justice of the curia regis, who died about 1209 [see under Warenne, William de, d. 1138].
Warenne had livery of his lands on 12 May 1202 (Rot. Lit. Pat. p. 10). The loss of Normandy in 1204 deprived him of Bellencombre and his other ancestral estates in that duchy. However, his English interests were much greater than his Norman ones, and he remained faithful to John. On 19 April 1205 he received from John, as a recompense for his fidelity, a grant of Grantham and Stamford to be held until John reconquered Normandy or made Warenne a competent exchange for it (Rot. Lit. Claus. p. 28). The right of tallaging Stamford, save by royal precept, was expressly withheld, but on 9 June John allowed him to exact a tallage from that town (Rot. Lit. Claus. p. 37). In February 1206 he was one of those escorting William, king of Scotland, on his visit to England (Rot. Lit. Pat. p. 56). In 1206 Warenne was in France with the king (ib. p. 74). On 20 Aug. 1212 he and two others received the custody of the castles of Bamborough and Newcastle-on-Tyne, and of the bailiwick of the county of Northumberland during pleasure (Rot. Lit. Pat. p. 94). He had to purge himself of a suspicion of treason before he was allowed possession (ib. p. 94 b). In September 1212 he took charge of Geoffrey, son of Geoffrey de Say, whom John held as a hostage (Rot. Lit. Claus. p. 124). In the troubles of John, first with the pope and then with his barons, Warenne was one of the little group of nobles closely related to the royal house which adhered to the king as long as was possible. He was one of the four barons who, at Dover on 13 May 1213, swore by the king's soul that John would observe his promise of submission to Innocent III and Archbishop Langton (Rog. Wend. iii. 249, Engl. Hist. Soc.), and on 15 May he attested John's resignation of his crown into Pandulf's hands (ib. iii. 254). He was one of those directed by Innocent III, on 31 Oct. 1213, to complete and keep the peace between John and the English church (Rot. Lit. Pat. p. 39). On 21 Nov. 1214 he attested John's charter of freedom of election to the churches (Select Charters, p. 289). On the same day the king allowed him to take twenty deer in the royal forests in Essex (Rot. Lit. Claus. p. 178). On 15 Jan. 1215 he was granted a house in the London Jewry by the king (Rot. Cartarum, p. 203). In the final struggle for Magna Carta he was one of the few magnates who adhered to John until the defection of London (Rog. Wend. iii. 300). Even after that he did not join the confederates in the capital; and on 15 June was present at Runnymede (ib. iii. 302), though most of his knights deserted him for the popular cause (Ralph Coggeshall, p. 171). He was one of the king's ‘fideles’ by whose council Magna Carta was issued (ib. p. 296). He was one of the ‘obsecutores et observatores’ of the charter, who swore to obey the mandates of the twenty-five executors (Matt. Paris, ii. 605). In November 1215 he was among the king's representatives at a conference with the Londoners in Erith church to treat of peace (Rot. Lit. Pat. p. 158). In January 1216, however, he seems to have wavered in his fidelity, and some of his lands were taken into the king's hands (ib. p. 246). Yet he soon came back to the king, who on 15 Jan. gave him all the lands of the king's enemies in Norfolk among his own sub-tenants (ib. p. 245), and on 26 Jan. directed his officers to keep his lands in peace and restore any that had been taken from him (ib. p. 246). On 26 May he was made warden of the Cinque ports ‘because the king does not want to put a foreigner over them’ (Rot. Lit. Pat. p. 184); while on 1 June John empowered him to receive the rebels back to their allegiance (ib. p. 185). By this time, however, Louis of France had been received in London, and Warenne at last deserted the king he had served so long (Rog. Wend. iii. 369); though so late as 17 Oct. John's order to Falkes de Breauté to release the men of Earl Warenne whom his servants had captured suggests that the king had hopes of bringing him back to his side (Rot. Lit. Claus. p. 291).
On 17 Jan. 1216–17 Warenne was commanded by Honorius III to return to the allegiance of Henry III (Cal. Papal Letters, 1198–1304, p. 43). In April 1217 he made a truce for eight days with the regent Pembroke (Fœdera, i. 146), and subsequently abandoned Louis for the service of the little Henry III (Rog. Wend. iv. 12). He was rewarded with various grants of lands. On 24 Aug., according to one manuscript of Matthew Paris, he was present at the sea fight with Eustace the Monk off Dover (Matt. Paris, iii. 28–9). Between 1217 and 1226 he was sheriff of Surrey, William
