ONSLOW, Denzil (c.1642-1721), of Pyrford, Surr.

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



11 Nov. 1680 - Jan. 1681
1689 - 1695
1695 - 1698
Feb. 1701 - 1713
12 Mar. 1714 - 10 Dec. 1717
25 Dec. 1717 - 27 June 1721

Family and Education

b. c. 1642, 8th s. of Sir Richard Onslow† of Knowle, Surr. by Elizabeth, da. of Sir Arthur Strangeways of Holborn Bridge, London; bro. of Sir Arthur Onslow†.  educ. I. Temple, 1663.  m. (1) 14 Aug. 1671, Sarah (d. 1705), da. of Sir Thomas Foot, 1st Bt.†, Grocer, of London, alderman of London 1643–8, 1660, ld. mayor 1649–50, and wid. of Sir John Lewis, 1st Bt., of Ledston, Yorks. s.p. (2) Jane (d. 1729), da. of Henry Weston† of Ockham, Surr., sis. of John Weston*, and wid. of Robert Yard* of Westminster, under-sec. of state 1694–1702, s.p.1

Offices Held

Out-ranger, Windsor Forest 1686–?1711, 1718–d.; commr. victualling the navy 1706–11, 1714–d.2

Freeman, Guildford 1675.3


Born with all the advantages afforded by one of Surrey’s most well-established households, Denzil Onslow achieved a prominence within his lifetime which faithfully reflected the limits of his personal ambition. Succinctly portrayed by his great-nephew Arthur Onslow† as ‘a younger brother with a scanty provision, bred to no business, having soon left that he was designed for, with very moderate abilities of any kind’, his career was marked by opportunism and good fortune. In December 1661 he had been apprenticed to William Peake, a London citizen, but trade was evidently not to his liking. A more astute move was to secure the prize of a double heiress, Sarah Lewis, though he was merely following the example of his brother Arthur in marrying a daughter of the wealthy London merchant Sir Thomas Foot. The most important consequence of this match was the purchase of a country seat at Pyrford in 1677, where Onslow proved himself a most industrious landowner. Only four years later, John Evelyn was to congratulate ‘this worthy gentleman’ for the improvements made on the estate while also praising the ‘extraordinary feast’ provided for Onslow’s guests. The death of his father-in-law in 1688 swelled his annual income to some £2,000 p.a., a considerable fortune which easily qualified him as a leading county figure, irrespective of his family’s influence.4

Not surprisingly Onslow’s wealth and social standing soon encouraged him to aspire to a parliamentary seat. With great difficulty and amid much contention, he managed to secure a first electoral success at Haslemere during the Exclusion crisis. The borough was some distance from the main concentration of Onslow estates at the heart of the shire, but Denzil succeeded in regaining the seat in the aftermath of the Revolution. Moreover, his office of out-ranger of Windsor Forest helped to consolidate his family’s influence in the north of the county. While benefiting him personally to the tune of £600 p.a., the post also established a link with the court that was to be an enduring feature of his political career.

Onslow’s performance in the House itself was less certain in terms of impact, although, as befitting the godson and namesake of Denzil Holles†, he evidently shared his family’s Whiggish principles. Having supported the Sacheverell clause in the last days of the Convention, he was identified by Lord Carmarthen (Sir Thomas Osborne†) as a Whig supporter at the opening of the 1690 Parliament. Conflicting reports of his political outlook were subsequently echoed by Robert Harley* and Carmarthen, the former citing him as a Country supporter in 1691, the latter describing him as a member of the Court party a year later. This confusion may simply reflect Onslow’s obscurity on the back benches, for Samuel Grascome endorsed Carmarthen’s verdict in the course of 1693, and further testimony to the fact that he was a ‘friend to the government’ came in September 1694. However, the actual extent of his political activity at Westminster remains less clear. The Journals make little attempt to distinguish between Denzil and his nephew Foot Onslow*, although the latter can be credited as the more active MP of the two. Even after 40 years in the House, as his great-nephew Arthur later wrote, Denzil ‘knew no more of the business there than one who had been but of the standing of a session’.5

In spite of this apparent lack of parliamentary prominence, the general election of 1695 saw a notable rise in ambition on Onslow’s part as he successfully stood for one of the county seats alongside his nephew Sir Richard Onslow, 3rd Bt.* He only managed to beat off the challenge of Edward Harvey* by 24 votes, and then had to face an inquiry by the committee of privileges after Harvey alleged that some of Denzil’s supporters had falsely sworn themselves as qualified freeholders. Once the House had upheld Onslow’s election on 16 Jan. 1696, he proved a solid supporter of the Court, being forecast to support it in the division on the council of trade later that month, and voting to set the price of guineas at 22s. in late March. In this session, he also appeared at least twice in the Journals: as a teller on 17 Feb. 1696 in opposition to going to the question on a motion to postpone the assizes for two weeks, and as a subscriber to the Association ten days later.

In November of that year, Onslow gave further proof of his Whiggish opinions by supporting the attainder of Sir John Fenwick†, even though his county colleague Sir Richard voted against it. His desultory appearance in the House was also maintained in the following sessions of the 1695–8 Parliament with only one definite action of significance, as a teller in support of a motion on 20 Jan. 1698 that all royal grants since the Restoration be laid before Parliament. His petition for leave of absence on 10 May 1698 was thus well in keeping with his parliamentary profile, and the general election of that year would exemplify his political reticence. Although he had given little intimation of standing again, it was rumoured on the eve of the poll that ‘upon second thoughts’ he would contest the election alongside his nephew. However, the appearance of five other candidates to challenge the Onslow platform was sufficient to cause his withdrawal. The Onslows were still reeling from a scandal surrounding the prior election of Foot Onslow at Guildford, a situation which recommended that the family dare not antagonize the country gentlemen by attempting to take both county seats for a second successive Parliament.6

In this contentious atmosphere there was no alternative seat available for Onslow, and he therefore had to wait until the next general election before a vacancy occurred in a constituency where his family’s interest was well established. Foot Onslow’s decision to resign his seat at Guildford in June 1700 in preference for an excise post gave Denzil the opportunity to return to Parliament in the following February, and he found little trouble in maintaining his place there for the next six elections. However, the election of his great-nephew Thomas Onslow* soon afterwards undermines any attempt to chart his parliamentary activity, and the first definite and noteworthy reference to Denzil in his second spell in the Commons does not occur until January 1709.

Yet in political terms Onslow remained a solid Whig supporter, described as such by Harley in December 1701. In the first Parliament of the new reign, he voted on 13 Feb. 1703 in favour of the Lords’ amendment to debar MPs who refused the abjuration oath from being reinstated at a later date. He then voted against the Tack, having been forecast as one of its likely opponents, and was subsequently described by one analyst of the House as a ‘Low Churchman’ in 1705. He also maintained a close association with the Court in the next Parliament, backing its candidate for Speaker on 25 Oct. 1705, and voting against the ‘place clause’ annexed to the regency bill in the key division of 18 Feb. 1706. Only four months later, such political loyalty was rewarded with his appointment as one of the six commissioners at the naval victualling office, a lucrative post with a salary of £400 p.a. The timing of this appointment was particularly fortunate for he had lost ‘the best part of his income’ on the recent death of his wife. His first marriage had not been happy, principally due to Onslow’s extramarital affairs, and his punishment was to see his wife’s relatives from her first marriage named as the chief beneficiaries of her will.7

Dependent on his offices for the bulk of his income until his second marriage, Onslow had to rely more heavily on his parliamentary standing in order ‘to keep up his post in the country’. He was twice identified as a Whig in early 1708, and this same steadfastness was revealed in the next Parliament by his support of the naturalization of the Palatines early in 1709. His responsibilities at the victualling office brought him to the House’s attention on 17 Jan. 1709, when he acted as a co-presenter of a report concerning contracts for goods supplied to the fleets which had taken part in the Peninsular campaign. His enduring interest in the affairs of his Surrey constituents was also highlighted in this session by his management of a bill to permit the transportation of slaughtered cattle to Smithfield market. On 22 Feb. he acted as a teller in favour of the passage of this bill and was ordered to take it up to the Lords. His reputation for good-neighbourliness was also upheld in that session when he was named on 4 Apr. as a trustee for a private estate bill introduced by Lord William Powlett*.8

In the next session, Onslow’s name was again linked to metropolitan and county matters, he being named to drafting committees on bills to regulate hackney carriages, to establish a Surrey land registry, and to vest an estate in the hands of hospital governors. Although he remained inconspicuous, the heightened political temperature of this session and its aftermath caused him considerable financial problems. In early 1710 he had supported Sacheverell’s impeachment and thus became one of the targets of a vigorous campaign by Surrey Tories at the ensuing general election. Ill-health initially threatened to make him withdraw, but he managed to secure his seat despite a bitter contest over the second Guildford seat. In the first session of the 1710–13 Parliament he was forced to secure two grants of leave of absence from the House on health grounds. He suffered further discomfort in the course of the year when he lost both his offices ‘for refusing to comply with the then measures of the Court in Parliament’. In the House itself he was one of the few Whigs appointed on 15 Nov. to the committee to investigate complaints against the poor Palatines. But in spite of losing his posts, he maintained his Whiggish principles by voting for the motion of ‘No Peace without Spain’ on 7 Dec.

In consideration of such difficult personal and political circumstances, the absence of any clear reference to further activity on Onslow’s part in the 1710–13 Parliament is hardly surprising. The uncertain position of both his family and his party at the next election was reflected in his decision to allow his seat to pass to his nephew Sir Richard, whose candidacy at Guildford was a direct result of a galling defeat at the county poll of 1710. Sir Richard’s success at the subsequent shire election gave Denzil the opportunity to regain his old seat, but the resulting by-election saw a strong challenge from the Tory John Walter†. For a second time Onslow had to justify his place in the House before the committee of privileges, where on 1 Apr. 1714 there was ‘a long debate that lasted till late at night’. However, despite the allegations of ‘illegal practices’ which Walter levelled against the mayor and town clerk of Guildford, the Commons upheld Onslow’s election on 27 Apr.9

This troubled period in Onslow’s career ended with the passing of the Tory ministry, following which he quickly regained his post at the victualling office, and succeeded his great-nephew Thomas a few years later as out-ranger of Windsor Forest. Such political favour was matched by electoral success, for he eventually secured the more prestigious county seat at a contested by-election in December 1717, again following in the footsteps of his great-nephew. He died on 27 June 1721, by which time, as another great-nephew, Speaker Onslow, observed, he had achieved considerable stature in his county based on his easy manner with all ranks of society. Of more direct political significance, his local standing remained a key element in his family’s control of the shire, since Denzil ‘always by his own interest at every county election brought in the greatest body of freeholders that appeared there’. However, an obituarist’s claim that he was ‘ever a strenuous asserter of the liberties of England’ probably came closest to pinpointing the political priorities of this quintessential back-bench figure. After two childless marriages his real and personal estate (the latter including a ring containing a lock of King William’s hair) eventually passed to his great-nephew Thomas.10

Ref Volumes: 1690-1715

Author: Perry Gauci


  • 1. Manning and Bray, Surr. iii. 54; IGI Yorks.; Cam. Soc. n.s. xxii. 79.
  • 2. CSP Dom. 1686–7, p. 315; Luttrell, Brief Relation, vi. 54.
  • 3. Surr. RO (Guildford), BR/OC/1/3, f. 168.
  • 4. HMC 14th Rep. IX, 495; Clothworkers’ Hall mss, apprentice bk. 1641–62; Evelyn Diary, iv. 255.
  • 5. HMC Downshire, i. 449; HMC 14th Rep. IX, 496.
  • 6. BL, Evelyn mss, [–] to John Evelyn, 8 Nov. 1695.
  • 7. HMC 14th Rep. IX, 496; HMC Hastings, ii. 236.
  • 8. HMC 14th Rep. IX, 496; HMC Lords, n.s. viii. 301.
  • 9. Bath mss at Longleat House, Portland misc. pprs. bdle. of letters to Robert Harley, memo. on elections [?1710]; HMC 14th Rep. IX, 496; EHR, lxxxiii. 483; Boyer, Pol. State, vii. 308.
  • 10. Cal. Treas. Bks. xxxii. 194; HMC 14th Rep. IX, 495–7; Boyer, xxi. 672; PCC 136 Buckingham.