did not last long. In the winter of 1259–1260, when Henry III and Simon de Montfort were both at Paris, a reconciliation was effected. Before Henry left England on 14 Nov. he begged Simon to make terms with his brothers, and the death of Aymer on 4 Dec. at Paris made agreement easier. William and Simon patched up a peace, the terms of which were afterwards disputed (Bémont, Simon de Montfort, p. 350, prints an interesting document from the Archives Nationales, which gives full details). In February 1260 he was one of Henry's agents in negotiating with the French (Fœdera, i. 394). About Easter 1261 William returned with Edward to England, where he was allowed to land on swearing to obey the provisions (Rishanger, p. 9, Rolls Ser.; Flores Hist. ii. 466), and on 30 April was fully restored by Henry III at Rochester (Cal. Rot. Pat. p. 33; Pauli, iii. 745, is here a year wrong). In 1262 William again attended Henry III to France (Foedera, i. 422), where he reconciled the king with the young Gilbert of Gloucester (Cont. Gerv. Cant. ii. 216). On 5 Feb. 1263 he was again ambassador to Louis (Royal Letters, ii. 239). In 1263 the Londoners devastated his lands (Wykes, p. 141). Early in 1264, under Edward's directions, he devastated the country round Oxford, and in April was with Henry at the siege of Northampton. On 14 May he fought for the king at Lewes, being stationed with Warenne under Edward on the right wing. He was one of those who escaped after the battle, with Warenne, to Pevensey, whence they crossed over to France. In England William's possessions were now forfeited, the custody of Pembroke Castle being on 6 June committed to Gloucester (Cal. Rot. Pat. p. 35). Early in May 1265 William landed with Warenne in Pembrokeshire with a strong force of crossbowmen and knights (Flores Hist. iii. 264). He joined Edward and Gloucester and took a large share in the royalist restoration, participating in the siege of Gloucester in June (Royal Letters, ii. 288), the attack on Kenilworth on 1 Aug. (Liber de Ant. Legibus, p. 74), and in the battle of Evesham. Next year, in May, he joined Warenne in attacking the monks and townsmen of Bury St. Edmunds (Cont. Flor. Wig. ii. 197). He was abundantly rewarded. His former lands and castles were restored. He was granted the wardship of Haverfordwest during Humphrey de Bohun's minority, and several forfeited estates, including that of his brother-in-law Munchensi, were transferred to him (for grants after 1265, see Rot. Cartarum, pp. 97–9). Henceforth he remained a good Englishman (Ann. Dunstaple, p. 400).
On 24 June 1268 William renewed his crusader's vow at Northampton, when Edward himself took the cross (Wykes, p. 218). He was in Ireland in the spring of 1270 (Cal. Doc. Ireland, 1252–84, p. 141), but on 20 Aug. he sailed for the Holy Land with Edward (Ann. Winchester, p. 109). He came back to London on 11 Jan. 1273, somewhat earlier than his nephew (Liber de Ant. Legibus, p. 156), bringing with him from Palestine a cross of gold and emeralds, which ultimately became the property of Westminster Abbey (Testamenta Vetusta, i. 100). He was one of the executors of the will drawn up by Edward at Acre on 18 June 1272 (Fœdera, i. 484).
Under Edward I William devoted much energy to increasing the limits and the jurisdiction of the Pembroke palatinate. This only included the region between Milford Haven and the Bristol Channel; but William strove to establish his supremacy over all the neighbouring marchers in a district somewhat wider than the modern Pembrokeshire. He was helped by his appointment on 12 May 1275 as constable of Cilgerran Castle and warden of St. Clears during pleasure at a rent of 40l. (Deputy Keeper of Publ. Rec. 44th Rep. p. 277). This attempt involved him in a series of lawsuits with Queen Eleanor—to whom the barony of Haverfordwest had been transferred—and others (see Cal. Pat. Rolls, 1281–92 pp. 330, 398, 1292–1301 pp. 49, 114; Rot. Parl. i. 30–2, 84, 138). In Archenfield and Gwent he improved his position when in July 1275 he obtained dispensations for marrying his daughter Isabella to John de Hastings (1262–1313) [q. v.], lord of Abergavenny, a minor (Cal. Papal Letters, 1198–1304, p. 450). On 6 July 1282 he received the custody of Abergavenny for the rest of his son-in-law's minority (Cal. Patent Rolls, 1281–1292, p. 30).
William's estates in Wales gave him a particular importance during the wars against Llewelyn. On 6 July 1282 he was appointed commander of the army of West Wales, which on 6 Dec. mustered before him at Carmarthen (Parl. Writs. i. 227, 244). This year his son William was slain near Llandeilo by the Welsh (Ann. Dunstaple, p. 292; Wykes, p. 289; Rishanger, p. 100). He was again summoned against the Welsh on 2 May 1283 at Carmarthen (Parl. Writs. i. 247). In the same year his capture of the Snowdonian stronghold of Bere secured the surrender of Davydd ap Gruffydd (Rishanger, p. 104). Before 1289
