and was in attendance upon Philip, duke of Bavaria.
The accession of Edward VI brought fresh honours to Mason, and he was dubbed a knight of the carpet either at the coronation on Sunday, 20 Feb., or the Tuesday following, which was Shrove Tuesday. In the same year he visited the county of Rochester as one of the royal visitors, and in 1548 was appointed by the Protector to search the registers for ‘records of matters of Scotland’ in order to establish the English claim of suzerainty over Scotland. The result of his researches was a collection of instruments preserved in Harleian MS. 6128 in the British Museum. He was paid 20l. for his labour (Acts of the Privy Council, 1542–7, p. 225; Harl. MS. 6128). In 1549 he gave evidence against Bonner, and was made dean of Winchester. Mason was one of the commissioners who negotiated the treaty with France (Wriothesley, Chronicle, Camden Soc., ii. 31), surrendering Boulogne, 24 March 1549–1550 (Cotton MS. Caligula E. iv.) On 18 April 1550 he was appointed ambassador to France, and after being sworn a privy councillor next day, he set out for Paris on 12 May. Thenceforward his letters to the council formed one of the most important sources of intelligence respecting foreign affairs. In September he was negotiating about the Scottish frontier disputes (Add. MS. 5935; Acts of the Privy Council, 1547–1553). Old-standing complications between England and France, and the growing readiness of the French to interfere in Scottish affairs rendered Mason's post no sinecure. His health, too, was failing, and within a year he petitioned for recall; he had already been granted license to eat flesh during Lent, and early in 1551 he complained of being so feeble that it was pain even to dictate to an amanuensis. On 25 Feb. his appointment was revoked, with expressions of regret for his illness and commendation for his services; but his successor, Sir William Pickering [q. v.], delayed settling in Paris, and Mason, much against his will, still held office in May, when he and the Marquis of Northampton arranged for the betrothal of Edward VI to Elizabeth, the French king's daughter (cf. Add. MS. 5498, ff. 16–20, 100; Froude, v. 3–5). He appears to have been also sent to the emperor at this time, probably to support the English ambassador, Dr. Wotton (Edward VI's Journal; Froude, v. 6–7). He was finally recalled from Paris on 30 June, but only reached England at the end of July. In September he resumed his attendance at the privy council, and about the same time became master of requests. In December, together with Francis Spelman, a connection by marriage, he was granted the office of clerk of parliament. In 1552 he was on a commission to collect ‘church stuff’ (Strype, Memorials, ii. i. 210), and in the same year, profiting as usual by every turn of the wheel, he and his wife were granted lands in Middlesex which had belonged to Somerset, and others in Berkshire and Kent (ib. pp. 221, 223, 226). He appears as member of parliament for Reading in 1551–2, for Taunton in 1552–3 (Foster, Alumni Oxon. 1500–1714), and on 18 Nov. 1552 became chancellor of Oxford University, a dignity which he resigned in 1556 in favour of Cardinal Pole. Mason was one of the witnesses to the will of Edward VI on 21 June 1553, and signed the letter of the council to Mary on 9 July, informing her that Jane had been proclaimed queen, and counselling submission. He had thus lent himself to the designs of Northumberland. But with his habitual insight he saw how the tide was running, and on 19 July he helped to arrange with the lord mayor for the proclamation of Queen Mary (Chronicle of Queen Jane, p. 12). The next day he signed the order of the council requiring Northumberland to lay down his arms (ib. p. 109).
Mason was soon high in Mary's favour. Although he held no ecclesiastical office during the reign, his secular preferments were restored to him. He attended the council when in England, and in 1554 he was made treasurer of the chamber, his salary for this office and the mastership of the posts being 240l. a year and 12d. a day. In the same year he was elected for Southampton, which he represented till his death. In October 1553 he was appointed ambassador to the emperor's court at Brussels, and remained there busily employed until 1556. He arranged for the return of Pole, of whom he spoke highly; had several interviews with the emperor, and was present in October 1555 at the ceremony of Charles's abdication at Brussels, his account of which has been frequently quoted (cf. Motley, Dutch Republic, i. 110). In the same year it was rumoured that he was to be recalled and made chief secretary (Cal. State Papers, Venetian, vol. vi. pt. i. p. 245), but a request for leave to return home in July 1556, granted by Mary, was negatived by Philip (ib. p. 555). Mason was on friendly terms with most of the English residents abroad, and in 1556 Dr. John Caius the younger [q. v.] dedicated to him an edition of his ‘De Medendi Methodo,’ reprinted at Louvain. Early in May Sir Peter Carew [q. v.] and Sir John Cheke [q. v.], whose wife was Mason's stepdaughter, were
