ONSLOW, Thomas (1679-1740), of Clandon, Surr.

Published in The History of Parliament: the House of Commons 1715-1754, ed. R. Sedgwick, 1970
Available from Boydell and Brewer



1702 - 1705
26 Nov. 1705 - 1708
1708 - Nov. 1715
30 Nov. 1715 - 5 Dec. 1717

Family and Education

bap. 27 Nov. 1679, o. surv. s. of Richard Onslow, 1st Baron Onslow. m. (1) 17 Nov. 1708 (with about £70,000), Elizabeth, da. and h. of John Knight, merchant of Jamaica, niece and h. of Col. Charles Knight, also of Jamaica, 1s. suc. fa. as 2nd Baron Onslow 5 Dec. 1717.

Offices Held

Outranger of Windsor Great Park 1715-17; ld. lt. Surr. and high steward, Guildford 1717-d.; teller of the Exchequer 1718-d.


At George I’s accession Thomas Onslow spoke on the address to the new King, observing that in this case the occasion was one for congratulation rather than condolence. Re-elected in 1715, he spoke on 21 June in defence of the Duke of Ormonde. In November he succeeded his father as knight of the shire for Surrey, vacating his Bletchingley seat by taking an office of £600 p.a.1 On 20 Feb. 1717 he moved the Address, his last recorded speech before being called to the Lords by his father’s death. He continued to play a leading part in Surrey elections, complaining in 1720 to Sunderland of the expense to which he was being put

in promoting his Majesty’s service in the county of Surrey, which I fear must fall without his Majesty’s kind support and your Lordship’s assistance.

And again in 1722:

I am now going to another election ... but now depend on your Lordship’s goodness and promise, or will never more engage, for ’tis ruin to my family, and the fatigue of so many elections intolerable.2

A figure in the City, he presided in 1720 over the insurance company known at the time as ‘Onslow’s Bubble’, which survives today as the Royal Exchange Assurance. He married a West Indian heiress, with whose money he rebuilt Clandon by Leoni. According to his cousin, the Speaker, he

was not without parts and spirit and some knowledge of the world, and had a notion of magnificence suited to his rank and fortune, but had such a mixture of what was wrong in everything he thought, said and did, and had so much of pride and covetousness too, that his behaviour, conversation, and dealings with people were generally distasteful and sometimes shocking, and had many bitter enemies but with very few friends.3

He died 5 June 1740.

Ref Volumes: 1715-1754

Author: Romney R. Sedgwick


  • 1. HMC 14th Rep. IX, 494-5.
  • 2. Sunderland (Blenheim) mss.
  • 3. HMC 14th Rep. IX, 494-5.