O’BRIEN, Henry, 7th Earl of Thomond [I] (1688-1741), of Great Billing, Northants. and co. Clare

Published in The History of Parliament: the House of Commons 1690-1715, ed. D. Hayton, E. Cruickshanks, S. Handley, 2002
Available from Boydell and Brewer



1710 - 19 Oct. 1714

Family and Education

b. 14 Aug. 1688, o. s. of Henry Horatio O’Brien, Ld. O’Brien (3rd s. d.v.p. of Henry O’Brien, 6th Earl of Thomond [I]) by Lady Henrietta, da. of Henry Somerset†, 1st Duke of Beaufort, and sis. of Charles Somerset*, Mq. of Worcester.  m. 14 June 1707, Lady Elizabeth (d. 1734), da. of Charles Seymour, 6th Duke of Somerset, s.psuc. fa. 1690, gdfa. as 7th Earl of Thomond [I] 2 May 1691; cr. Visct. Tadcaster 19 Oct. 1714.

Offices Held

PC [I] 1714.

Gov. co. Clare and co. Carlow 1714; ld. lt. Essex 1722–d.


Lord Thomond was descended from an ancient Irish family (closely related to the earls of Inchiquin), with extensive property in county Clare. His great-grandfather bought the estate of Great Billing in the reign of James I and his grandfather was a colourful and eccentric figure at the courts of Charles II and James II. Thomond’s father had declared for William of Orange in 1688 against the wishes of the 6th Earl, and on his death in July 1690 a contemporary wrote, ‘I think my Lord O’Brien’s death, he being mad without hope of recovery, a blessing both to his own family and his wife’s’. His grandfather died a year later, leaving him and his vast estates to the care and guardianship of his mother, an arrangement which ultimately proved somewhat unfortunate. The family’s financial affairs, particularly in Ireland, were in some confusion, although in 1702 he was left a considerable fortune by his aunt, the widow of Sir Joseph Williamson*. Early in February 1704, his kinsman, Sir Donat O’Brien, advised Thomond’s mother, Lady O’Brien, to arrange a match for him:

as he is now come above his father’s age when he espoused you . . . and not to insist so much upon the greatness of a fortune for him as her own worth . . . before he gets out of your power into such an acquaintance as perhaps may divert him from it.

Lady O’Brien ignored this advice, being herself at this time involved with Lord Walden (Henry Howard*) whose late wife had been her husband’s sister. A correspondent wrote to Sir Donat O’Brien on 2 Dec. 1704:

I find this ancient noble family’s going headlong to ruin, through the pretended piety and virtue of the precious, chaste and charitable Lady Harriet, and the tender affection honest Lord Walden has for the young Earl and his charmed mother.

Shortly after this, Lady O’Brien married Lord Walden. Thomond himself remained devoted to his mother and stepfather, despite attempts by his grandmother (the Duchess of Beaufort), the Duke and Duchess of Ormond and other relatives to detach him and despite allegations that the newlyweds were living at his expense, running up huge debts to be paid out of his estate, and that Lord Walden had misapplied some £20,000 of his money. At one stage it was alleged that the household was living at the rate of £30,000 p.a., but Thomond was nevertheless still very rich on his marriage in 1707.1

In 1709 Thomond unsuccessfully contested a by-election at Cirencester on the interest of Thomas Onslow*, but was returned in 1710 for Arundel on the interest of his stepfather (now Earl of Suffolk), who had previously sat for the borough, and no doubt also with the support of his father-in-law, the Duke of Somerset. Classed as a Whig on the ‘Hanover list’ of 1710, he was rather surprisingly included on the list of ‘worthy patriots’ who in the first session of this Parliament exposed the mismanagements of the previous administration. He did, however, vote for the Whig motion of ‘No Peace without Spain’ on 7 Dec. 1711. Given leave of absence for 21 days on 25 Mar. 1712, Thomond was not particularly active in the House. He secured two private bills, one in 1711 and another in 1713 enabling him to grant freehold leases on his estates, although by the terms of his marriage settlement he only held his property on a life tenancy. In the Commons, on 18 June 1713, he voted against the French commerce bill. Continuing to represent Arundel after the 1713 election, he was classed as a Whig on the Worsley list of this Parliament, was teller on 5 Mar. 1714 in favour of hearing the Whigs’ petition against the London election, and voted on 18 Mar. against the expulsion of Richard Steele. An active supporter of the Hanoverian succession, Thomond was raised to the English peerage as Viscount Tadcaster in October 1714. He died on 20 Apr. 1741 in Dublin and was buried in Limerick Cathedral. His estates were inherited by his nephew by marriage, Percy Wyndham†, who took the name of O’Brien. His viscountcy became extinct, but his Irish titles were eventually inherited by the earls of Inchiquin.2

Ref Volumes: 1690-1715

Author: Paula Watson


  • 1. Inchiquin Mss (Irish Mss Commn.), 78, 81, 82, 85, 88, 91; Baker, Northants. i. 20–21; HMC Finch, ii. 401; Beaufort mss at Badminton House, Earl of Clarendon (Henry Hyde†) to Duke of Beaufort, 5 Nov. 1702; Add. 17677 CCC, f. 144.
  • 2. Beaufort mss, Earl of Suffolk to Lady Anne Coventry, 12 Jan. 1710; Add. 70420, newsletter 27 Dec. 1710; Inchiquin Mss. 524.