Hamelin as earl occurs in the pipe roll of 10 Henry II (Pipe Roll Soc. vi. 30, vii. 92). Like William of Blois, Isabella's first husband, Hamelin is henceforward called ‘Comes de Warenne’ and lord of his wife's great estates in Yorkshire, Surrey, Sussex, and Norfolk. He is rarely, if ever, described by contemporaries as ‘Earl of Surrey.’
Hamelin took a fairly conspicuous part in politics. He was at the council of Northampton in October 1164, and joined in the denunciation of Archbishop Thomas (1118?–1170) [q. v.] as a traitor. He was crushed by the archbishop's taunt, ‘Were I a knight and not a priest, this hand should prove thee a liar’ (Materials for the History of Thomas Becket, i. 39–40, iv. 52). After Becket's exile he was sternly rebuked by the primate for withholding the tithes of the monks of Lewes (ib. vi. 372–3). However, in after years he became a great worshipper of St. Thomas, being cured, as was believed, of blindness in one eye by means of the covering of the shrine of the martyr (ib. i. 452). This established a close connection between him and the monks of Christ Church, Canterbury, who, in their hour of supreme need, during their contest with Archbishop Baldwin in 1187 and 1188, made urgent appeals to his charity and sympathy (Epistolæ Cantuarienses, pp. 85, 264–5, 268).
In 1166 Hamelin was returned as possessing sixty knights' fees (Red Book of the Exchequer, i. 204), and in 1171–2 paid a scutage of 60l. to the exchequer (ib. i. 58). He was one of the few great nobles who remained faithful to Henry II during the general revolt of the feudal party in 1173–4 (Benedictus Abbas, i. 51). In August 1176 he acted as one of the escort of his niece Joan, Henry II's daughter, on her way from England to the court of her husband, King William of Sicily. He accompanied Joan as far as St.-Gilles in Provence (ib. i. 120). He was faithful to his brother in the general desertion that preceded Henry II's death, being with him in June 1189 on the continent (Fœdera, i. 48). He was present at Richard I's coronation on 3 Sept. 1189. He exchanged with Richard his lands at Toron in France for Thetford in Norfolk (Hearne, Liber Niger Scaccarii, i. 371; the date limits of this charter are 5 June 1190–27 Nov. 1191). During his nephew's absence on crusade Hamelin upheld his government against the intrigues of Earl John. In 1191 he adhered to the chancellor Longchamp against John. He was sent by the chancellor to liberate Archbishop Geoffrey [q. v.] of York from prison (Gir. Cambr. Opera, iv. 395). He represented Longchamp at the conference with John's adherents at Loddon Bridge, near Reading (ib. iv. 398). At Winchester on 28 July he was one of the three earls appointed to represent the chancellor's party who, with other representatives of both sides, sought to appease the feud on conditions honourable to both parties (Richard of Devizes in Chron. Stephen, Hen. II, and Ric. I, iii. 409). In 1193 he was one of the treasurers of Richard's ransom (Rog. Hov. iii. 212), and on Richard's release he attended the great council held by the king at Nottingham in March 1194 (ib. iii. 241). He carried the second of the three swords borne before Richard at his second coronation on 17 April 1194.
On 27 May 1199 Hamelin was present at John's coronation (Rog. Hov. iv. 90), and on 21 Nov. of the same year witnessed the homage of the king of Scots to John on a hill near Lincoln (ib. iv. 141). In March 1201 he entertained John at Conisborough (Hunter, South Yorkshire, i. 107). He died in April 1202. Isabella de Warenne is said to have died on 13 July 1199 and to have been buried at Lewes, but the order to their tenants to do homage to their son on 12 May 1202 was made ‘salva fide matris suæ’ (Rot. Lit. Pat. p. 10 b), and a charter printed and facsimiled in Watson's ‘Earls of Warren and Surrey’ (i. 167) purports to be issued by her after her husband's death.
Hamelin had a long dispute with the abbots of Cluny as to their respective rights over the priory of Lewes (Cal. Papal Letters, 1198–1304, p. 186; Ralph of Diceto, ii. 173). He was a benefactor of Lewes and other houses. He and Isabella were also benefactors of the Augustinian priory of St. Mary Overy, Southwark (Monasticon, vi. 172), and to a small extent of St. Mary's, York. He founded an endowment for a priest for the chapel within Conisborough Castle. Probably he was the builder of the magnificent keep of Conisborough (G. T. Clark, Mediæval Military Architecture, i. 450; cf. Hunter, South Yorkshire, i. 107). His various grants are collected, though not very critically, in Watson (i. 160–2). His high-handed action with regard to his dependent churchmen is seen in a letter to Guy Rufus, rector of Conisborough, printed in ‘Historians of the Church of York’ (iii. 86, Rolls Ser.).
Hamelin was succeeded by his son, William de Warenne (d. 1240) [q. v.] He was the second founder of the house of Warenne. His paternal origin was forgotten, and the name Warenne became the family name of his descendants. His male line continued to hold the earldom until the death of John
