Osborne’s early life was dominated by his paternal grandfather, Thomas Osborne, duke of Leeds. As head of the family, it was Leeds who dictated the education of his grandchildren, not least because of the unstable conduct of his son and heir. It was at Leeds’ behest that Osborne and his elder brother, William Henry, styled earl of Danby, left for Holland on 1 Dec. 1706 to continue their education abroad. The two brothers were based at Utrecht from January 1707, learning riding, maths, dancing, fencing and music. They travelled extensively in the United Provinces and in September 1710 paid a visit to the court of Hanover.
In January 1712 Leeds made a new settlement of his estate, which ensured that his wayward son was passed over in favour of his grandson. His will, made a few days later, confirmed his intentions.
The question of Carmarthen’s marriage now came to the fore. To Swift his merits as a spouse were clear: ‘the young fellow has £60,000 ready money; three great houses furnished, £7,000 a year at present, and about five more after his father and mother die.’
The problem for both Carmarthen and Oxford remained the necessity of persuading Leeds to accept the settlement of the family’s estates. After much effort on Oxford’s part, in which he denied any underhand dealings, Leeds accepted the match, presumably because Oxford promised his assistance in procuring a renewal of the 1st duke’s pension from the post office.
Newly of age, with a legal title to the Osborne patrimony and with a close affinity to the lord treasurer, Carmarthen was an obvious candidate for bolstering the strength of the ministry in the Lords and a writ in acceleration was dated 29 Jan. 1713.
tomorrow being Monday your Lordship’s writ to call you up to the House of Lords will be sealed. The Parliament will meet on Tuesday, but be prorogued for a very few days, so that if your Lordship come to town tomorrow you may kiss her majesty’s hands, though I believe Lord Keeper will not be able to come to the House so that your Lordship cannot be then introduced.
Eg. 3385A, ff. 41-42.
In response Carmarthen proposed to wait on Oxford the following day, when Beaufort would be able to accompany him to thank Oxford for his ‘great kindness in advancing me to so unmerited an honour.’
Carmarthen was eventually introduced at the prorogation on 3 Mar. 1713 by his brother-in-law, George Hay, Baron Hay, styled Lord Dupplin [S] (also the future 8th earl of Kinnoull [S]) and Samuel Masham, Baron Masham. He then attended the prorogations on 10 and 17 March. At about this time his name appeared on a list in the hand of Jonathan Swift, with Oxford’s additions, as one of those expected to support the ministry, and just prior to the session, on 3 Apr., he wrote to congratulate Oxford ‘on the success of this great and glorious work of yours the peace’.
On 13 June 1713 Oxford forecast that Carmarthen would vote in support of the bill confirming the 8th and 9th articles of the French commercial treaty but on that very day told him that he should not stir until he had recovered from an indisposition.
now under almost the same difficulties with my father as before I was happily allied to your Lordship, in whose power it has been long and is still (pardon my thinking so) to free me from, and make me as easy in my circumstances and affairs as you have made me happy in a wife.Add. 70250, Carmarthen to Oxford, 18 June 1713, ‘State’ of ‘Carmarthen’s affairs in relation to Keeton’.
Chiefly, his problems with his father revolved around his Yorkshire estate and the depredations of the followers Leeds had installed on the properties. Carmarthen hoped that Oxford would be able to remove these difficulties by judicious use of his power of patronage, in effect compensating Leeds from public funds with either the post office pension or some equivalent.
From at least as early as May 1713 a settlement was being negotiated between Leeds and his son (and Oxford). In June Oxford wrote to Carmarthen setting out the options: ‘you know the difficulty of treating with him, and there is but two ways, one by law, which will be very tedious and the other by treaty in which I have offered him great advantages.’
The birth on 6 Nov. 1713 of a son, Thomas Osborne†, the future 4th duke of Leeds, was a cause of great pleasure to Carmarthen and his father. Simultaneously, it was reported that ‘Mr Williams is in quiet possession of Kiveton, found everything much better than was expected ... the furniture is in good order.’ The death of his wife at Wimbledon on 20 Nov. 1713, following complications after the birth, left Carmarthen ‘the most dejected man living, does not care to see to speak to anyone’, and designing to take solace in Yorkshire.
Carmarthen attended on the opening day of the 1714 Parliament on 16 February. He attended on 37 days of the session, 47 per cent of the total. On 8 Apr. Lady Dupplin reported that ‘Lord Carmarthen has had a cold but is better’, but on 10 Apr. he registered his proxy with Beaufort. He next sat on 28 April. He then registered another proxy on 13 May with his father. He did not sit again until 30 June, spending part of his absence in the country and part on a visit to Windsor.
At the time of Queen Anne’s death, Carmarthen was at Badminton but travelled to London for the Parliament taking his seat on 9 Aug. 1714.
Carmarthen continued to have a difficult relationship with his father, who spent some years in exile as a Jacobite, always imploring his son for more funds. He succeeded his father in 1729, but always susceptible to bouts of ill health he was an irregular attender in Parliament in his latter years. He died on 9 May 1731, at his house in Pall Mall, of a ‘consumptive illness’ and was buried at Harthill.
