Son of John Stuart (1713-1792), 3rd Earl of Bute and Prime Minister of Great Britain (1762-1763), and Mary Wortley Montagu (1718-1794). In 1766 he married Charlotte Hickman-Windsor (d. 1800) with whom he had at least six children. Following the death of his first wife in 1800, he married Frances Coutts (d. 1832) later that same year. With Frances, he had at least two children.
Mountstuart was educated at Winchester College and Oxford University, and from ca. 1757 had philosopher Adam Ferguson as his tutor.
He held the seat as Member of Parliament for Bossiney from 1766 to 1776, when he became Baron Cardiff and thus a member of the House of Lords. In the House of Commons, he was a supporter of the Chatham, Grafton and North administrations, although his relationship with the latter deteriorated until it reached a point where Mountstuart "said he would have knocked him [North] down, if it had not been in the House of Commons".1 He was later appointed British minister to Sardinia (1779-1783).
- 1According to Walpole quoted in Namier & Brooke's The House of Commons 1754-1790, entry Stuart, John, Lord Mounstuart.
Boswell and Mountstuart travelled together for a while in Italy in 1765. They parted on difficult terms, but by May 1766 their relationship seem to have improved.
It is unclear to which extent (if at all) James Boswell and Lord Mountstuart were acquainted before they both went on their Grand Tours of Europe. In any event, they both found themselves in Rome by February 1765, and Boswell's first mention of a meeting between them was on February 25, when he wrote "Then Lord Mountstuart's. He in bed. Quite Englishman." Boswell departed for Naples to see John Wilkes on the same day, and upon his return to Rome some weeks later, he began cultivating the company of Andrew Lumisden and other associates of the "court" of the Old Pretender. This could have made a closer relationship with Lord Mountstuart awkward, as his father was a former Prime Minister and a friend of King George III.
However, at the beginning of May, they met again, and on the second of that month Boswell dined with Mountstuart and made a note to "See Mountstuart often, as [he is a] good lad." On the next day, he described Mountstuart as "quite [a] man of fashion, fine air; true Stuart."
By early June, their friendship had become quite intimate, and Mountstuart desired Boswell to accompany him for his further travels in Italy. However, at this point, Boswell had been abroad for almost 2 years - and away from his native Scotland for 2½ - and he was being pressed by his father to return home. Therefore, Mountstuart wrote a remarkable letter to William Mure, Baron of Exchequer, writing among other things:
"Having got acquainted with Mr. Boswell here at Rome, our acquaintance soon grew into a strong intimacy - so much so, that I have desired him to go on with me in my tour through Italy, as long as it would be agreeable to him. He liked the scheme much [...] but says he is so much pressed by his father to go home that he durst not take such a step without his leave; but that you, being a great friend of my Lord's, might easily obtain permission. Boswell is an excellent lad, full of spirit and noble sentiments; and (as the world goes) it ought to be reckoned a fortunate thing for him going with me, and indeed fortunate for myself, as he goes on in the same studies as I do, and , if possible, rouses me up whether I will or no. [...] Now, my dear Mure, I hope you will tell all this to his father; also that his cousin, the Colonel, wishes it much. You may tell him, too, that I am not so wild a man as I am generally supposed to be."1
On June 14 the two set out from Rome, and for the next 6 weeks, they accompanied each other through Italy. Their friendship soon deteriorated, however, due to a combination of a tendency to childish jokes on Mountstuart's part (according to Boswell) and an inappropriate level of familiarity on that of Boswell's (according to Mountstuart). Eventually, on July 26, Boswell wrote in his journal:
"[Yesterday, d]ined at Bergamo. Disputes with my Lord. He said, 'I shall always esteem you, but you're most disagreeable to live with. Sad temper,' &c. Smiled to hear this."
Boswell also made a note to himself to "Have long conference with my Lord and own being in wrong, not for obstinacy but loose conduct. Say sorry, and you'll be on guard. Bid him be prudent not to say follies of you, as you've been free with him."2
On the next day they took leave of each other with Mountstuart beginning his journey back to England, as he had been recalled by his father. Boswell went on to Siena and Corsica, before returning to England almost six months later.
Eventually, Boswell sent a letter to Mountstuart, the exact content of which is unknown. It is referred to in a remarkable and very personal reply from Mountstuart, dated May 29, 1766:
"MY DEAR BOSWELL: [...] You seem so desirous to keep up an acquaintance with me that I begin to think that you like me as well as you say, yet I think, the strange incoherency of your temper makes it dangerous to render that acquaintance intimate, you have fine old noble ideas, as I us'd to tell you; but the least thing alters you the last man you see, of whom you have an opinion carries away yours, add to that, I think you a little dangerous to trust, for you are glad to exult whenever you can lay hold of an opportunity [...] but to lay aside this nonsense, I am much oblig'd to you for those expressions of warmth towards me in your letter and receive them as you desire I should; and be assur'd that in spite of your oddities I take you to be a most excellent good hearted man and as such, will do every thing in my power (without shew and affectation) to oblige you and whatever you may do, I shall always have that regard and friendship for you I had at Rome." 3
In the summer of 1766 Boswell finished and defended his thesis, and on July 29 was admitted advocate. The thesis was dedicated to Mountstuart (with permission, this time), causing Dr. Johnson to ask Boswell "Why did you dedicate it to a man whom I know you do not much love?"4
- 1Extract of a letter from Lord Mountstuart to Baron Mure dated June 5, 1765 from Rome. Quoted in Boswell on the Grand Tour 1765-66
- 2 Journal entry July 26, 1765. Quoted in Boswell on the Grand Tour 1765-66
- 3Extract of letter from Lord Mountstuart to James Boswell dated May 29, 1766 in London. Quoted in The General Correspondence of James Boswel, 1766-67
- 4Letter from Johnson to Boswell of August 21, 1766, printed in Boswell in Search of a Wife