probably a Lacy (Liber Niger Scacc. ed. Hearne, p. 155). William entered public life at the close of Henry's reign as official to the king's son Geoffrey [see Geoffrey, d. 1212] for the archdeaconry of Rouen. Henry warned his son that the traitor blood would show itself before long, and the warning seemed justified when William deserted Geoffrey's service for that of Richard, who made him his chancellor for the duchy of Aquitaine. Longchamp was in Paris about April 1189 when William Marshal [q. v.] and Ralph, archdeacon of Hereford, arrived there to negotiate peace between Henry II and Philip Augustus. By his ‘guile’ in Richard's interests Longchamp is said to have counterchecked the envoys' efforts (Histoire de Guillaume le Maréchal, ll. 8323–30, ed. Paul Meyer). On Richard's accession to the crown William became chancellor of the kingdom and bishop of Ely. Consecrated on 31 Dec. 1189, he was enthroned at Ely on 6 Jan. 1190. The king moreover, before leaving England in December, had given him the custody of the Tower of London, and chosen him to share with Bishop Hugh of Durham the office of chief justiciar. William was a man of considerable ability, energetic, hard-working, and devoted to his sovereign, but he was generally unpopular. Personally he was ugly, stunted, deformed, lame, and his manners were as unattractive as his appearance. He was a stranger in England, and took no pains to make himself at home there; he knew no English, and did not try to learn; indeed, he paraded his contempt for the land and its people in a fashion which stirred the resentment of all classes. He was jealous of his high-born fellow-justiciar Hugh Pudsey, bishop of Durham, who looked down upon him as an upstart interloper. They quarrelled as soon as the king's back was turned. William shut Hugh out from a meeting of the court of exchequer, and took upon himself the whole viceregal authority, even to annulling appointments made by Richard in person—conduct for which he, as chancellor, doubtless had the royal sanction. In February 1190, when Richard called a council in Normandy, William hurried over in advance of his colleagues to anticipate their complaints against him, and returned in triumph as sole chief justiciar in Hugh's stead.
William began his administration by fortifying the Tower; in April he went to punish a riot at York; while there he learned that Hugh was on his way home with a fresh commission as justiciar over Northumberland. The rivals met at Blyth, Nottinghamshire, and again at Tickhill, Yorkshire, where William produced a letter, of later date than Hugh's credentials, from Richard to himself, appointing him supreme representative of the absent king. Hugh was forced to surrender his claims, and a commission as legate for all England, granted on 5 June by Pope Clement III, made William supreme in both church and state. As legate he, at Richard's desire, absolved John from an oath to keep out of England for three years [see John, king of England]. John's return threatened William's authority, and he strove to assert it by holding a church council at Gloucester, in the heart of John's lands, on 1 Aug., and another at Westminster on 13 Oct., followed by a progress throughout the realm. Thereby he only added to his unpopularity; for the entertainment of his train of a thousand men-at-arms, and the exactions which he made in the king's name, were so ruinous to the districts through which he travelled that a contemporary writer compares his passage to that of a flash of lightning. The general discontent found a rallying-point in John, who early in 1191 came to England, and at once set himself in opposition to the chancellor. On Mid-Lent Sunday the rivals met at Winchester; the meeting ended in a quarrel. Immediately afterwards Gerard de Camville, the sheriff of Lincolnshire and constable of Lincoln Castle, proclaimed himself John's liegeman, and defied the chancellor openly. William, who at the moment was busy in Herefordshire punishing Roger Mortimer for treasonable dealings with the Welsh, hurried back to find Lincoln impregnable, Nottingham and Tickhill in the hands of John, his own legatine commission suspended by the death of the pope, and his viceregal authority threatened by the impending arrival of Archbishop Walter of Rouen [see Coutances, Walter of] as special commissioner from the king. He therefore submitted his dispute with John to arbitration at Winchester on 25 April; the arbitrators decided against him on every point. Nevertheless, at the end of June he ventured to deprive Gerard de Camville of his sheriffdom. The other bishops, headed now by Walter of Rouen, called a meeting at Winchester on 28 July, and there made a fresh settlement somewhat more favourable to William (Stubbs, notes to Gesta Ric. p. 208, and Rog. Hoveden, iii. 134). On 30 July William issued a writ for the arrest of Geoffrey, now archbishop of York, as soon as he should touch English soil, Geoffrey having, like John, taken a vow of absence for three years, and William having no assurance that it had been remitted by Richard. The arrest was forcibly made on 18 Sept., in St. Martin's Priory Church, near Dover, by