Inchinnan, &c., in Renfrewshire (ib. No. 2791), and the lordship of Lennox (ib. No. 2972), Robert Stewart having resigned these lands in his favour, and receiving instead the lordship of March.
Playing for such high stakes, Lennox did not scruple to forswear himself to the utmost extent that the circumstances demanded. According to Calderwood, he purchased a supersedere from being troubled for a year for religion (History, iii. 460); but the ministers of Edinburgh were so vehement in their denunciation of the ‘atheists and papists’ with whom the king consorted that the king was compelled to grant their request that Lennox should confer with them on points of religion (Moysie, Memoirs, p. 26). This Lennox, according to the programme arranged beforehand with the Guises, willingly did; and undertook to give a final decision by 1 June. As was to be expected, he on that day publicly declared himself to have been converted to protestantism (Reg. P. C. Scotl. iii. 289); and on 14 July he penned a letter beginning thus: ‘It is not, I think, unknown to you how it hath pleased God of his infinite goodness to call me by his grace and mercy to the knowledge of my salvation, since my coming in this land;’ and ending with a ‘free and humble offer of due obedience,’ and the hope ‘to be participant in all time coming’ of their ‘godly prayers and favours’ (Calderwood, iii. 469). A little later he expressed a desire to have a minister in his house for ‘the exercise of true religion;’ and the assembly resolved to supply one from among the pastors of the French kirk in London (ib. p. 477). On 13 Sept. he is mentioned as keeper of Dumbarton Castle (Reg. P. C. Scotl. iii. 306), and on 11 Oct. Lennox was nominated lord chancellor and first gentleman of the royal chamber. In the excessive deference he showed to the kirk Lennox was mainly actuated by desire for the overthrow of Morton. Although regarded by Mary and the catholics as their arch enemy, Morton was secretly detested by the kirk authorities. His sole recommendation was his alliance with Elizabeth and his opposition to Mary; but the kirk having, as they thought, obtained a new champion in Lennox, were not merely content to sacrifice Morton, but contemplated his downfall and even his execution with almost open satisfaction. When Morton was brought before the council on 6 Jan. 1580–1 and accused of Darnley's murder, Lennox declined to vote one way or other, on the ground of his near relationship to the victim; but it was perfectly well known that the apprehension was made at his instance, and that Captain James Stewart (afterwards Earl of Arran [q. v.]) was merely his instrument. Randolph, the English ambassador, had declined to hold communication with Lennox, on the ground that he was an agent of the pope and the house of Guise (Randolph to Walsingham, 22 Jan. 1580–1, quoted in Tytler, ed. 1864, iv. 32), as was proved by an intercepted letter of the archbishop of Glasgow to the pope; but Lennox had no scruple in flatly denying this, the king stating that Lennox was anxious for the fullest investigation, and would ‘refuse no manner of trial to justify himself from so false a slander’ (the king and council's answer to Mr. Randolph, 1 Feb. 1580–1, ib.) After the execution of Morton on 6 June 1581 the influence of Lennox, not merely with the king but in Scotland generally, had reached its zenith. So perfect was the harmony between him and the kirk that even Mary Stuart herself became suspicious that he might intend to betray her interests and throw in his lot with the protestants (Mary to Beaton, 10 Sept. 1581 in Labanoff, v. 258); but the assurances of the Duke of Guise dispelled her doubts (ib. p. 278). On 5 Aug. 1581 he was created duke (Reg. P. C. Scotl. iii. 413), and on the 12th he was appointed master of the wardrobe.
As early as April 1581 De Tassis had, in the name of Mary, assured Philip II of Spain of the firm resolution of the young king to embrace Roman catholicism, and had sent an earnest request for a force to assist in effecting the projected revolution. It was further proposed that James should meanwhile be sent to Spain, in order that he might be secure from attempts against his crown and liberty; that he might be educated in catholicism, and that arrangements might be completed for his marriage to a Spanish princess. To the objection that Lennox, having special relations with France, might not be favourable to such a project, De Tassis answered that he was wholly devoted to the cause of the Queen of Scots, and ready if necessary to break with France in order to promote her interests (De Tassis to Philip II in Relations Politiques, v. 224–8). For the furtherance of these designs, Lennox early in 1582 was secretly visited by two jesuits, Creighton and Holt, who asked him to take command of an army to be raised by Philip II for the invasion of England, in order to set Mary at liberty and restore catholicism. In a letter to De Tassis, Lennox expressed his readiness to undertake the execution of the project (ib. pp. 235–6); and in a letter of the same date to Mary he proposed that he should go to France to raise