from storms and sickness, reached Valladolid 18 Feb. 1512–13. He had received (30 Jan.) a commission dated 13 Dec. 1512, authorising him and John Stile to treat with Ferdinand of Aragon about the defence of the church. A long letter from Stile and Knight in cipher (of 3 March) is preserved in the British Museum (Cotton. MS. Vesp. C. i. 30). Knight remained at Valladolid till June 1513. On 3 April 1514 he was at Mechlin on the first of a long series of embassies to the Low Countries (cf. letter in Cotton. MS. Galba, B. iii. 13). Wingfield and Spinelly were with him (18 April), and on 12 June he was at the Hague with Sir Edward Poynings. In July he seems to have visited Switzerland (cf. misdated letter ib. Vesp. F. i. 54). Probably to better qualify him for diplomatic work, as well as in reward for past services, he received, on 14 July 1514, a grant of arms (party per fess or and gules, an eagle with two heads displayed sable; on its breast a demi-rose and a demi-sun conjoined into one, counterchanged of the field). In the grant he is described as prothonotary.
In May 1515 Knight is styled chaplain to the king, and in that month Henry lent him 100l.; in the same year he became dean of the collegiate church of Newark, Leicestershire. On 7 May he was appointed ambassador with Sir Edward Poynings to Prince Charles (afterwards Charles V), to renew the league of 9 Feb. 1505. They had a conference with Tunstal, 23 May, at Bruges, and an audience with Charles at Bergen-op-Zoom on 29 May. He remained in Flanders during the rest of 1515, and, like most of Henry's servants, found himself in pecuniary straits (cf. Letters and Papers, Henry VIII, ii. i. 1235). In February 1515–16 the treaty had been concluded (cf. Rymer, Fœdera, xiii. 533, 539). He probably came to England in 1516, as he was in that year collated to the prebend of Farrendon-cum-Balderton in the cathedral of Lincoln (Le Neve, Fasti, ii. 150). On 30 Dec. 1516 he was, in company with the Earl of Worcester, again appointed ambassador to the emperor (for his instructions see Letters and Papers, ii. i. 2713), and he had an interview with Charles, 22 Jan. 1516–17. Throughout 1518 he was English representative to the Lady Margaret in the Low Countries, and sailed home from Calais 15 Feb. 1518–19. As one of Henry's chaplains and clerk of the closet he was at the Field of the Cloth of Gold in 1520 (Rutland Papers, Camden Soc., p. 33); and seems to have been made prebendary of Llanvair in Bangor Cathedral in the same year (Le Neve, i. 120). On 10 June 1520 he was commissioned, with Sir Thomas More, John Hussee, and Hewester, to settle the disputes between the English merchants and the Teutonic Hanse, and went again to the Netherlands (cf. Letters and Papers, iii. i. 868, 974). Sir Richard Wingfield, writing from Oudenard, 28 Oct. 1521, reported that Knight was to take his place as ambassador to the emperor (ib. iii. ii. 1712), but it seems (ib. iii. ii. 1777) that the emperor objected to his low birth, and expressed a preference for Wingfield's brother, Sir Robert (ib. iii. ii. 2033, February 1521–2). Knight made a journey on diplomatic business into Switzerland in 1522; went on an embassy to the empire respecting the woolstaple, and was (11 Nov.) admitted archdeacon of Chester. In 1523 he concluded with the Duke of Bourbon a treaty against France (ib. iii. ii. 3123, instructions; 3203, 3225, account of the journey), but was back at Brussels in August. On 11 Sept. 1523 he was appointed archdeacon of Huntingdon (Le Neve, ii. 52). The next few years he chiefly passed in Flanders. About August 1526 he became secretary to the king.
In 1527, though he complained that he was old and losing his sight (Letters and Papers, iv. ii. 3360), Henry decided to send him to Rome to promote the divorce. Wolsey thought Jerome de Ghinucci, bishop of Worcester, would have been better suited for the work (ib. iv. ii. 3400). On 10 Sept. Knight saw Wolsey at Compiègne, and by his direction went on to Venice to watch for an opportunity to get access to the captive Pope Clement VII (ib. iv. ii. 3420; cf. 3422–4, 3497). The journey was dangerous from the disposition of the Spaniards, but he managed to get a safe-conduct by the aid of Gambara the prothonotary. He was, however, well-nigh murdered at Monterotundo (4 Dec. 1527), and when he entered Rome all that he could do was to send in his letters of credence with a minute of what the king wished (ib. iv. ii. 3638; cf. Froude, Catherine of Aragon, p. 51). On 19 Dec. 1527 Knight, while still in Italy, was made canon of Westminster. By the end of December, Jerningham wrote that the secret of Knight's negotiation had not been so well kept as it should have been, and that the emperor now knew Knight's business, and had written to the pope accordingly (Letters and Papers, iv. ii. 3687). Full instructions were thereupon sent to Knight, with a commission to Wolsey and another, which, if signed by the pope, would have empowered them to settle the divorce (ib. iv. ii. 3693; 3694, copy of bull). On 1 Jan. 1527–8, the pope being now at liberty, Knight visited him at Orvieto, and after Cardinal St. Quatuor (to whom two thousand crowns were given) had made some alterations in the commission,
