Three years later, when the king's sons rebelled, Hugh, perhaps influenced by his connection with the French court, for the first time endeavoured to play an important part in political affairs. Though he did not actually join in the rebellion, he permitted William the Lion to enter England unopposed in 1173, and in January 1174 held a conference with the Scottish king at Revedale and purchased a truce for himself for three hundred marks (Ralph de Diceto, i. 376; Gesta Henrici, i. 64). He also fortified Northallerton Castle, and put it in charge of his nephew Hugh, count of Bar, who brought over a force of Fleming mercenaries to his uncle's aid. When the failure of the rebellion was manifest, Hugh came to the king at Northampton on 31 July. But his temporising policy had displeased Henry, and the bishop had to purchase peace by the surrender of his castles of Durham, Norham, and Northallerton; it was with difficulty that he could obtain permission for his nephew and his Flemings to go home undisturbed (ib. i. 73).
During 1174 Hugh made an agreement with Roger of York as to the rights of Hexham and the churches belonging to the see of Durham in Yorkshire (Rog. Hov. ii. 70–1; Raine, Historians of Church of York, iii. 79–81). He was with the king at Woodstock and Nottingham in July–August 1175, and at Westminster in March 1176 (Eyton, Itinerary, pp. 192–3, 200). In March 1177 he was again present in the council at Westminster when the king arbitrated between the kings of Castile and Navarre, and in the following May was allowed to purchase his peace for two thousand marks and obtained a grant of the manor of Whitton for his son Henry. About this time Northallerton Castle was dismantled; nor does the bishop appear to have recovered his castles of Norham and Durham till somewhat later (Gesta Henrici, i. 160). After keeping Christmas 1178 with the king at Windsor, Hugh went abroad to attend the Lateran council at Rome in March 1179. In the following year he was commissioned with Roger of York to excommunicate William the Lion for his action with reference to the bishopric of St. Andrews. In 1181 Hugh and Roger, by the pope's orders, threatened the clergy of St. Andrews with suspension, and put Scotland under an interdict. Hugh was afterwards, in 1182, present at the meeting of Bishop John of St. Andrews with the papal legates (ib. i. 263, 281–282). On 26 June 1181 he had been employed on another papal commission at London on the matter of the dispute between the monks of St. Augustine's, Canterbury, and the archbishop (Gervase of Canterbury, i. 296). Roger of York had died in November 1181, and the long vacancy of the northern primacy which ensued tended to increase Hugh's power and importance. After Roger's death Hugh refused to account to the king for three hundred marks which he had received from the archbishop for charity. Henry, in wrath, ordered the castle of Durham to be taken into his hands; but Hugh's disgrace was not of long duration. He seems to have owed his reconciliation to the king to Geoffrey, the future archbishop of York (Gir. Cambr. iv. 367). He was with Henry at Windsor for Christmas 1184, and in the following March was present at the council at Clerkenwell, where, like many other magnates, he took the cross. On 16 April he passed over to Normandy with the king, and seems to have spent the next twelve months abroad. In March 1186 Henry sent him back to England; Hugh rejoined the king at Carlisle in July, and during the autumn was with Henry at Marlborough and Winchester (Ralph de Diceto, ii. 33–4; Eyton, Itinerary, pp. 263–273). He was at Canterbury on 11 Feb. 1187, when Henry intervened in the dispute between Archbishop Baldwin and the monks of Christchurch, and was afterwards one of the bishops to whom the monks appealed in January 1188 (Gerv. Cant. i. 353; Epistolæ Cantuarienses, p. 148). At the council of Geddington in February 1188, when the news of the fall of Jerusalem was considered, Hugh, with many others, renewed his crusading vows, and afterwards was sent to collect the Saladin tithe from William the Lion, whom he met for this purpose at Birgham in Lothian.
During the last years of the reign of Henry II Hugh had been taking a more prominent part in general English politics. The commencement of the new reign, and the intention of Richard to go on the crusade, opened to him the opportunity to turn his position in the north and his accumulated wealth to further advantage. The appointment of Geoffrey, the new king's half-brother, to be archbishop of York, threatened to interfere with his plans, and Hugh at once joined with Hubert Walter in appealing against the election. On 3 Sept. he was present at Richard's coronation, and walked on the king's right hand. In the subsequent general sale of offices Hugh's wealth placed him at a great advantage; the manor of Sadberge was purchased for his see for six hundred marks, and for the earldom of Northumberland he paid two thousand marks. The latter transaction Richard completed with a jest, saying: ‘See what a fine workman I am, who have made
