Duncombe’s ancestors settled in Buckinghamshire prior to the Reformation, leasing Wingrave rectory from St. Albans abbey. The family continued to hold this property until 1606, when Duncombe granted it away to Lord Ellesmere (Sir Thomas Egerton†). Brought up at Maids’ Moreton, just outside Buckingham, Duncombe trained as a lawyer, but he was never called to the bar, and instead practised as an attorney in the courts of Common Pleas and Exchequer. His forebears included William Russell, gentleman of the horse to one of the Tudor earls of Bedford. How far this Bedford connection directly influenced Duncombe’s own career is uncertain, but by the early seventeenth century Duncombe had certainly entered the circle of the 3rd earl, and was returned for Tavistock on the latter’s interest in 1604.
Duncombe made a confident start to his Commons’ career, with 25 recorded speeches and 34 committee appointments during this Parliament. His principal concern from the outset was religion. Named on 25 Apr. 1604 to help scrutinize the bill to deny benefit of clergy in cases of manslaughter by stabbing, he was entrusted with this measure on 13 June, though in the event it was reported by a kindred spirit, Nicholas Fuller. Duncombe was also appointed to legislative committees on scandalous clergy and church attendance, and in the latter case proposed that the bill should be stiffened by requiring irregular attenders to take communion annually (12 and 27 June). Duncombe moved on 21 June for a conference with the Lords to address two attacks on the House, namely the demand by Convocation that the Commons should stop meddling in religious affairs, and Bishop Thornborough’s pamphlet accusing Members of dragging their feet over Union with Scotland. This motion was accepted, and Duncombe was duly appointed to attend the conference.
Duncombe presumably attended the start of the second session before its disruption by the Gunpowder Plot. On 27 Jan. 1606 he visited Westminster Hall to see the arraignment of the surviving conspirators, and the next day backed Samuel Lewkenor’s complaint that the seating provided for Members at the trial was inadequate. Unsurprisingly, he once again supported tougher penalties against recusancy, and on 28 Feb. revived his earlier proposal of an annual sacramental test for Catholic conformists. On 5 Mar., apparently commenting on the leaking of Commons’ debates to the king, he highlighted the case of one Member, whom he declined to name, who had allegedly refused to vote for supply unless deprived puritan ministers were restored to their livings. Duncombe was named to committees to consider how to improve ecclesiastical government, and to investigate an ‘invective sermon’ preached at Paul’s Cross by the precentor of Lincoln cathedral (25 Mar., 26 May). He was also nominated on 14 Feb. to a committee to determine the fees payable in courts of record.
Religious affairs remained Duncombe’s primary concern during the 1606-7 session. On 26 Feb. he introduced a bill against ‘disorders in ministers’, and was appointed on 9 Mar. to its committee. Following the bill’s report on 2 May, he and the veteran puritan Sir Anthony Cope joined forces to attack assorted Anglican ceremonies of which they disapproved, apparently also affirming that the clergy should be subject to secular discipline. The measure passed its third reading, but failed to pass into law.
Appointed on 24 Nov. to hear the Lords’ proposals for the Union, Duncombe clearly lacked enthusiasm for this project. Relatively unconcerned by Sir Christopher Pigott’s outburst against the Scots, which resulted in the Buckinghamshire Member’s imprisonment, he ignored the Commons’ consensus on 28 Feb., and proposed unsuccessfully that Pigott be readmitted to the House. On the vexed issues of naturalization and the abolition of the hostile laws, he twice argued that the Commons should not compromise over its objections, but rather leave the Lords to take the legislative initiative (28 Mar. and 13 June).
The fourth session as usual found Duncombe busy with religious business. He was nominated to the committees for bills on pluralistic and nonresident clergy, subscription to the Church of England’s canons, and recusancy (19 Feb., 14 Mar., 16 Apr. and 8 May 1610). He was also appointed on 18 May to inquire into allegations that Sir John Davies, who was seeking to have his attainder reversed, had converted to Catholicism. On 30 Apr. he moved that the sub-committee on grievances might pen a preamble on ecclesiastical issues.
Duncombe was himself granted privilege on 18 May against a subpoena obtained in Chancery by one Henry Winston; the men who delivered it were apprehended, but released without further punishment five days later.
It is unlikely that Duncombe bothered to canvass the voters of Tavistock about the Contract during the recess. Certainly, he returned to Westminster for the fifth session in no mood to compromise. In essence, he now wanted concessions from the Crown on a wider range of issues, arguing on 2 Nov. that there was ‘no possibility to answer the king before we have examined the grievances and their answer’. On the following day, he conceded that most Members were resolved to continue negotiations, and advised that the Commons should respond positively to James’s complaints about the slow rate of progress. Nevertheless, he still considered that ‘there was just cause to suspect this business’, given the king’s failure to address Members’ concerns on other fronts. He elaborated his views on 8 Nov., singling out deprived ministers, the administration of four English counties by the Council for Wales, royal proclamations, and impositions as the most urgent grievances.
Re-elected at Tavistock in 1614, Duncombe was now recognized as one of the Commons’ more prominent Members. Named on 8 Apr. to the committee for privileges, he was also appointed to help prepare the bill for repeal or continuance of statutes, and to attend the conference on the Palatine marriage bill (8 and 14 April). From the outset he courted controversy, on 8 Apr. querying whether Sir Francis Bacon, as attorney-general, should be barred from serving in the Commons as precedent dictated. Bacon’s predecessor, Sir Henry Hobart, had actually sat in the Lower House during the previous Parliament, but only on the basis that he was already a Member at the time of his appointment. Bacon, in contrast, had become attorney-general prior to his election. The committee of inquiry to which Duncombe was named that day shared his concerns. Although the House subsequently ruled that Bacon should retain his seat, the principle was reaffirmed that such a key Crown servant should not be allowed into the Commons.
As usual, Duncombe was to the fore on matters of religion. On 9 Apr. he was appointed, along with Sir James Perrot, Nicholas Fuller and the clerk of the Commons, to supervise Members’ corporate communion. Having moved the second reading of the Sabbath observance bill on 7 May, he was duly named to the committee. He was also nominated to scrutinize the bill to abolish the ex officio oath (31 May). Surprisingly, he objected to the bill against extravagant clothing, arguing that it would unfairly limit expressions of female vanity, and bar gentlemen from wearing gilded spurs or swords (5 May).
Outraged by the bishop of Lincoln’s attack on the Commons’ campaign against impositions, Duncombe declared on 25 May that Neile was ‘worthy to have his head set on Tower Hill’ if it was true that he had ‘thus taxed the House’, and backed calls for business to be suspended while Members sought redress. When the king questioned whether the Commons had actually invaded his prerogative and terminated the session, Duncombe moved promptly for the whole House in committee to consider its reply (27 May). However, he dismissed Sir Edward Hoby’s attempt on 30 May to excuse the bishop’s remarks, and proposed a committee to devise some way permanently to record Neile’s unworthiness.
Duncombe owned some leasehold property on the Woburn estate, the earl of Bedford’s principal seat. In 1618-19, acting on the countess’s behalf, he became a joint patentee for the collection of old debts owed to the Crown, and of arrears of a long-forgotten duty on sea-coal. He seems not to have stood for election to the 1621 Parliament, perhaps because patronage at Tavistock now lay with Sir Francis Russell*, who had taken possession of the earl’s Devon estates four years earlier. However, after the ‘old debts’ patent was attacked on 21 Mar. as a grievance, Duncombe and his fellow patentees were ordered to bring the offending grant into the Commons. The records do not reveal whether they complied. Duncombe died, unmarried and childless, in March 1634. Neither will nor administration grant has been found, and nothing further is known of his family.