MANSEL or MAUNSELL, JOHN (d. 1265), keeper of the seal and counsellor of Henry III, was the son of a country priest (Matt. Paris, v. , v. 129), a circumstance which probably explains the allegation that he was of illegitimate birth (Placita de quo warranto, p. 749). Weever, however, says that he had seen a pedigree showing his descent from Philip de Mansel, who came over with the Conqueror (Funerall Monuments, p. 273), and Burke makes him a descendant of Henry Mansel, eldest son of Philip (Dormant and Extinct Peerage, p. 354), but these statements are opposed to the known facts. Mansel was brought up from early youth at court (Fœdera, i. 414), but the first mention of him is on 5 July 1234, when he was appointed to reside at the exchequer of receipt and to have one roll of the said receipt (Madox, Exchequer, ii. 51). The office thus created seems to have been a new one, and was probably that of chancellor of the exchequer, which is first spoken of by name a few years later. Soon after Easter 1238 Henry III despatched a force under Henry de Trubleville to aid the Emperor Frederick in his warfare with the cities of northern Italy. Mansel accompanied the expedition, and distinguished himself at the capture of various cities during the summer and in the warfare with the Milanese. After his return to England Mansel was in 1241 presented to the prebend of Thame by a papal provision, and in despite of the bishop, Robert Grosseteste. Grosseteste was highly indignant at the infringement of his rights, and Mansel rather than create trouble withdrew his claim, and obtained in recompense the benefices of Maidstone and Howden. Next year Mansel accompanied the king on his expedition to France, and distinguished himself in the fight at Saintes, on 22 July, when he unhorsed Peter Orige, seneschal of the Count of Boulogne. In the spring of 1243 Mansel was present at the siege of the monastery of Vérines, in the department of Charente-Inférieure; he again distinguished himself by his vigour and courage, and was severely wounded by a stone hurled from the wall. On his recovery after a long illness he rose yet higher in the royal favour, and in 1244 the king made him his chief counsellor. He had returned to England with the king in September 1243.
On 8 Nov. 1246 Mansel received custody of the great seal, which office he held till 28 Aug. 1247, when he surrendered it to go on an embassy for the king (Rot. Pat. 31 Hen. III, m. 2). He does not appear to have held the title of chancellor, for Matthew Paris speaks of him simply as ‘having custody of the seal to fill the office and duty of chancellor’ (iv. 601). The object of Mansel's foreign mission was to treat for a marriage between the king's son Edward and the daughter of the Duke of Brabant; the negotiations proved futile, and in 1248 Mansel returned to England. On 17 Aug. 1248 he again received custody of the great seal, and held it till 8 Sept. 1249. In October of the latter year he was taken ill, it was said from poison, at Maidstone. On 7 March 1250 he took the cross along with the king and many nobles. In June he was one of the entertainers of the general chapter of the Dominicans then being held in London.
As the foremost of the royal counsellors Mansel was employed by Henry to obtain the bishopric of Winchester for his half-brother Aymer [q. v.] in September 1250. His influence with the king enabled him to intercede successfully in behalf of Henry de Bathe [q. v.] and of Philip Lovel [q. v.], though in both cases his application was at first refused. He also interceded for Richard of Croxley, abbot of Westminster, and was appointed, together with Earl Richard of Cornwall, to arbitrate between the abbot and his convent. In these cases Mansel was acting on behalf of men who had been his colleagues in public life; more questionable was his support of his brother-in-law, Sir Geoffrey Childewike, in his quarrel with the abbey of St. Albans, which dispute was through his influence decided against the abbey (Matt. Paris, v. 129, 234; Gesta Abbatum, i. 315–20). Mansel himself was at this time (1251–2) engaged in a dispute with the abbey of Tewkesbury as to the tithes of Kingston Manor, he being then rector of Ferring, Sussex. The quarrel was decided by the arbitration of the bishop of Chichester (Ann. Mon. i. 147–9). In the autumn of 1251 he was employed on a mission to treat for peace with Scotland and arrange a marriage between Alexander III and Henry's daughter Margaret. In 1253 he accompanied the king to Gascony, and on 15 May was sent with William de Bitton, bishop of Bath and Wells, to treat with Alfonso of Castile; in this commission he is described as the king's secretary (Fœdera, i. 290). The object of the mission was to arrange for a marriage between the king's son Edward and Alfonso's sister; the mission was unsuccessful, but a second one in February 1254, in which Mansel also took part, fared better, and the treaty was signed on 1 April. In the following October Mansel was present at Burgos, on the occasion of Edward's marriage to Eleanor of Castile. During these negotiations he had obtained from Alfonso a charter renouncing any rights that he had in Gascony, and also the grant
