According to James II (Life, i. 490) this last appointment was not made nor the boy's instruction in the protestant religion begun till Charles II had resolved to send for him to England. In July 1662 ‘James Crofts,’ after being presented to the king at Hampton Court, accompanied him to Whitehall, where he was assigned apartments in the privy gallery. Grammont describes the furore created by his reception, but contrasts his deficiency in mental accomplishments with ‘the astonishing beauty of his outward form.’ As early as 31 Dec. 1662 Pepys mentions rumours of an intention to recognise him as the king's lawful son in the event of the marriage with the queen remaining childless. Scandal asserted (Grammont, p. 295) that the Duchess of Cleveland for the sake of her children made love to him, and that this gave rise to the plan of marrying him without delay. According to Clarendon (Life, ii. 253–6), Lauderdale, in order to baulk Albemarle's wish to secure this prize for his own son, suggested the choice of Anne Scott, by her father's death Countess of Buccleuch in her own right. She had 10,000l. a year, besides expectations. Disregarding Clarendon's advice, Charles II resolved to follow French precedent, and own his natural son. Accordingly on 14 Feb. 1663 ‘Mr. Crofts’ was created Baron Tyndale, Earl of Doncaster, and Duke of Monmouth (the title of Duke of Orkney having been abandoned); he received precedence over all dukes not of the blood royal (Pepys, 7 Feb.), and on 28 March was elected a K.G. (Collins). On 20 April of the same year ‘the little Duke of Monmouth’ (Pepys) was married to the Countess of Buccleuch ‘in the king's chamber,’ and on the same day (Collins) they were created Duke and Duchess of Buccleuch, and he took the surname of Scott. Already on 8 April 1663 he had been empowered to assume arms resembling the royal; on 22 April 1667 the royal arms themselves with the usual bar were granted to him ‘as the king's dear son’ (ib.) Honours military, civil, and academical were heaped upon him during the first decade of his dukedom. The fact that the king continued to ‘doat’ on his son (Pepys, 20 Jan., 8 and 22 Feb. 1664), even so far as to bestow a place at court upon the youth's maternal uncle (ib.), sufficiently accounts for the repeated revival of the rumour as to his intended legitimisation (ib. 15 May and 19 Nov. 1663, 11 Sept. and 7 Nov. 1667), and for the early suspicion that this fondness produced unkindness between the king and his brother (ib. 4 May 1663). Meanwhile Monmouth was ‘always in action, vaulting and leaping and clambering’ (ib. 26 July 1665), dancing in court masques (ib. 3 Feb. 1665), acting with his duchess in the ‘Indian Emperor’ (ib. 14 Jan. 1668), and accompanying the king to Newmarket for racing, to Bagshot for hunting, and on divers royal progresses (Historick Life, pp. 19–31). In 1665 he followed the fashion in volunteering under the Duke of York, and was present on 3 June at the battle in Solebay (Life of James II, i. 493). In the following year he obtained a troop of horse, preparatory to his being in 1668 named captain of the king's ‘life guard of horse’ (Historick Life, p. 20; cf. Pepys, s.d. 16 Sept. 1668). He was made a privy councillor in 1670, an ugly year for his reputation. He may be freely acquitted of the indirect share attributed to him in the death of the Duchess of Orleans, at whose interview at Dover with her brother he had assisted (Reresby, p. 82); but neither filial affection nor the brutality of the times can excuse his share in the assault upon Sir John Coventry [q. v.] for his reflection upon the king's intimacy with ‘female actors’ (ib.; cf. Burnet, i. 496). Dryden in his ‘Absalom and Achitophel,’ pt. i. l. 39, reproaches Monmouth under the character of Absalom with Amnon's (i.e. Coventry's) murder (cf. Scott and Saintsbury ad loc.) Coventry escaped with his life; not so an unfortunate beadle whom Monmouth and the young Duke of Albemarle killed as a sequel to beating the watch on 28 Feb. 1670 (see ‘On Three Dukes killing the Beadle,’ ap. Poems on Affairs of State).
When in January 1670 Monmouth succeeded Albemarle (Monck) as captain-general of all the king's forces, notwithstanding the opposition of the Duke of York, his first serious difference with the latter seems to have taken place (Life of James II, i. 494–5; cf. Dartmouth's note to Burnet, ii. 239). In 1672 he commanded the English auxiliary force against the Dutch under the eyes of Turenne and of Louis XIV himself, and on his return, in the company of the Earl of Feversham, to the seat of war in 1673, he took an active part in the siege of Maestricht, which capitulated on 2 July. ‘Much considered’ on account of his services (Burnet, ii. 19), he was fêted, pensioned, and, on letters commendatory from the king, elected chancellor of the university of Cambridge (15 July 1674). In 1674 or 1675 the chancellor danced in Crowne's ‘Calisto’ at court, when Lady Wentworth, afterwards his mistress, acted Jupiter (Crowne, Works, i. 248–9); before this he had been involved in an intrigue with Eleanor, daughter of Sir Robert Needham (Hist. MSS. Comm. 7th Rep. App. p. 305; cf. Horace Walpole, Letters, ed. Cunningham, i. 381 and note). In February
