16 Nov. Henry III died, whereupon Kirkby delivered up the seal to Archbishop Walter Giffard of York and the other councillors of the new king (ib. ii. 590). Under Edward I Kirkby remained attached to the chancery, and seems almost always to have been entrusted with the care of the great seal, when the chancellor, Bishop Burnell, was absent, either in his diocese or beyond sea. This was the case in February 1278, May 1279, February 1281, and March 1283 (Foss, iii. 111; Madox, Hist. of Exchequer, i. 71; Cal. Rot. Pat. pp. 48, 50). The name of vice-chancellor is given to him (‘Ann. Dunst.’ in Ann. Mon. iii. 305; Deputy-Keeper's Seventh Report, App. ii. 239), which suggests some sort of permanent official position. At least as early as 1276 he appears as a member of the royal council (Parl. Writs, i. 6).
In 1282 Edward I's finances were in a straitened condition through the expenses of the Welsh war. On 19 June he issued writs from Chester informing the sheriffs that he had appointed Kirkby as his commissioner for declaring verbally to all the shires (except Cornwall) certain arduous and important affairs (ib. i. 384). Walter of Agmondesham was associated with him, and all sheriffs and officials were instructed to assist him. Similar writs were sent to the boroughs, the religious houses, and the other local authorities. The object of Kirkby's mission was to persuade the various communities to make voluntary grants of money to the king. Kirkby spent the whole of the autumn in travelling about the country, and collected large sums of money. His mission is interesting as the last great attempt at carrying out the older conceptions of taxation, which rested on individual assent and grant (Stubbs, Const. Hist. ii. 124). Kirkby's activity drew upon him the anger of the monastic annalists (cf. Parl. Writs, i. 385, 387, 388; B. de Cotton, Hist. Angl. p. 162; the Continuator of Florence of Worcester, ii. 225, and the Dunstable and Worcester ‘Annals’ in Annales Monastici, iii. 302, iv. 487). But the sums collected were insufficient for the king's purpose. Edward therefore summoned two great parliamentary conventions of the clergy of the two provinces at York and Northampton, with meetings of lay representatives side by side with them. To the Northampton meeting Kirkby was sent as the royal representative on 5 Jan. 1283, along with Edmund, earl of Cornwall, and the abbot of Westminster, the treasurer (Parl. Writs, i. 11). Their exertions resulted in a grant by the commons of a thirtieth, from which, however, the sums previously collected by Kirkby were uniformly deducted (ib. i. 12).
Kirkby was rewarded for his services to the crown by so large a number of benefices that strict churchmen looked upon him as a scandalous pluralist. Though only in deacon's orders, and entirely occupied with affairs of state, he was rector of St. Buryan, Cornwall, dean of Wimborne, canon of Wells and York, and, after 1272, archdeacon of Coventry (Le Neve, Fasti Eccl. Angl. i. 568, ed. Hardy). In 1283 he was elected bishop of Rochester by the prior and convent of the cathedral. But Archbishop Peckham was resolutely opposed to rewarding mere officials with high ecclesiastical preferment, and exerted so much pressure that on 17 May Kirkby resigned his claims to the bishopric (Peckham, Letters, iii. 1032). Soon after the archbishop wrote to the monks of Rochester directing them to make a fresh election, on the ground that Kirkby's pluralism made him an impossible candidate (ib. ii. 575–6). Prynne (Records, iii. 359) wrongly states that Kirkby was elected bishop of Chester (Lichfield).
On 6 Jan. 1284 Kirkby was appointed treasurer in succession to the abbot of Westminster, who had died suddenly (Ann. Dunst. p. 305). He held this post until his death. Early in 1285 Kirkby had a hot dispute with the Londoners. The mayor, to avoid appearing before the treasurer at an inquest held in the Tower, resigned his office. Thereupon Kirkby took possession of the city, and directed all the leading citizens to appear next day before the king at Westminster. Edward ordered a large number into custody, and Kirkby appointed two agents to take the sheriffs' part in collecting the customary ferm of the city (‘Ann. Londin.’ in Chron. Edw. I and II, i. 94). In four days the prisoners were released, but the city was put under a warden, and did not recover its mayor until 1298 (Monumenta Gildhallæ Lond. i. 16–18, Rolls Ser.) Kirkby's high-handed action provoked much resentment.
From May 1286 to August 1289 Edward I was abroad. But on 8 July 1286 the king issued from Paris a license to the monks of Ely to elect a new bishop on the death of Hugh de Balsham [q. v.] On 26 July Kirkby was elected. Peckham offered no further opposition. On 7 Aug. Kirkby was presented before Edward at Melun, and on 17 Aug. Peckham confirmed the election at Saltwood in Kent. The temporalities were restored on 7 Sept., and on Saturday 21. Sept. Peckham himself ordained Kirkby priest at Faversham (Peckham, Letters, iii. 1041). Next day (22 Sept.) he consecrated him bishop at Canterbury (Stubbs, Registrum Sacrum
