Mervyn, Sir Audley (1603–75), soldier and MP, was the younger son of Sir Henry Mervyn of Wiltshire, England, admiral of the Narrow Seas, and his wife Christian Tuchet, daughter of George, Lord Audley, 1st earl of Castlehaven, and Lucy Mervyn. He entered Christ Church, Oxford, in 1618. Sir Henry and Lady Mervyn purchased the Tuchet plantation estates in Omagh and Clogher, Co. Tyrone, from her brother, the 2nd earl, and conveyed them to their older son James in 1626. James, a naval captain, secured a regrant of the property in 1630, took up residence, and died without issue on 10 July 1641. He was succeeded by Audley, who borrowed £1,000 on the statute staple some three weeks later. Their sister Deborah, widow of Leonard Blennerhassett, a Fermanagh plantation proprietor, had recently married Rory Maguire (qv).
Audley's arrival in Ireland is not recorded. He married Mary Windsor, daughter of Sir James Dillon (qv) of Castle Dillon, before July 1638 and was sufficiently established in Tyrone to secure election as county member to the Irish parliament in March 1640, before he came into his inheritance. When the ‘new army’ was commissioned to assist the king against the Scots in the following summer, he was appointed captain of a company in the regiment of Sir Henry Tichborne (qv). He was active in parliament from the outset and joined the leadership group of the opposition coalition early in 1641, when he was given responsibility for managing impeachment proceedings against the lord chancellor, the bishop of Derry, Sir Gerard Lowther (qv), and Sir George Radcliffe (qv). On 4 March he presented the charges to the house of lords in a prolix and highly coloured speech in which he urged the rule of law and called up images of Magna Charta ‘prostrated, besmeared and rolling on her bed’ and statute law on its death bed ‘stabbed by proclamations’ and ‘strangled by monopolies’ (A speech made by Captaine Audley Mervin . . . March 4, 1640 (London, 1641)).
The right to impeach was denied for want of precedent and Mervyn subsequently played a leading part in the vindication of the Irish parliament's power of judicature, most forcefully on 24 May when he commended to the lords a number of declarations adopted by the house of commons. His rebuttal of the official denial was grounded in the conviction that the Irish parliament was ‘co-heir with the parliament in England’, ‘founded upon the common laws of England’, and invested by Richard II (qv) with the rights ‘held by the subjects of England’. The right of judicature, in short, was inherent, irrespective of whether it had been previously exercised. He concluded by suggesting that a union of laws was the ‘best unity of kingdoms’ (Captaine Audley Mervin's speech . . . May 24 1641 (London, 1641)).
By his own account, some days after the outbreak of rebellion (October) Mervyn was asked by Rory Maguire to carry a message to the king: he refused, advised Rory to desist and the local protestants to take refuge, and made his own escape with his family. Thereafter, he shared the leadership of the British forces in the area with Sir William Stewart (qv) and served as colonel of a foot regiment throughout the war. He was among the officers who met in Belfast in January 1644 and decided to reject the English parliament's instruction to ignore the 1643 cessation and accept the Solemn League and Covenant. In February he appealed to Ormond (qv) to conduct the peace negotiations in association with the Irish parliament.
In April he attended the parliamentary session and took a leading part in the preparation of a proclamation proscribing the covenant. In the same month, Ormond sent him to Londonderry as governor with instructions to resist the adoption of the covenant there. Mervyn's contention that the covenant would prevent protestant unity was turned against him by both military and civilian opponents, and in the interests of that unity he was persuaded to avow it. His justification for doing so went beyond the pragmatic need to retain command: observing that second thoughts were a privilege ‘that the ablest judgements will not disclaim’ (Robert Stewart to Ormond, 26 May 1644, Bodl., Carte MS 11, f. 3), he maintained that those who had subscribed were well-disposed towards the king. The only reservation that he expressed arose from the covenant's assumption that the English parliament had authority over Ireland, and he urged that the Irish parliament should formally deny this.
When Ormond yielded authority to English parliamentary commissioners in 1647, Mervyn resisted the change and refused to cooperate with Sir Charles Coote (qv), who commanded the parliamentary forces in west Ulster. After Ormond's return, Mervyn was among those whose arrest was ordered by the English parliament on 4 November 1648, for fear that they would declare for the king. In December he was sent as a prisoner to London. He was released in May 1649 and, despite having sworn to live peaceably, resumed his command in the Laggan army which was assisting the siege of Coote's forces in Londonderry. In August Ormond appointed him as a delegate to discuss terms of cooperation with Owen Roe O'Neill (qv). He declined to act, reached an understanding with Coote instead, and abandoned arms.
Little is recorded of Mervyn's activities in the 1650s. He was in prison in Carlow in 1655, perhaps in connection with composition fines. He was admitted to the King's Inns in 1658 and was subsequently in practice, acting for Col. Hierome Sankey (qv) in his charges against William Petty (qv). In 1660 he was returned to the general convention of Ireland for Tyrone and was a member of the committee sent to negotiate with Charles II in May. Knighted by Charles on 19 July 1660, he was reported to have played an active part in the discussions that preceded the king's ‘gracious declaration’ of 30 November 1660 and was appointed a member of the commission charged with its execution, a role in which he acted, according to Lord Aungier, as ‘the most partial judge on earth’ (J. P. Prendergast, ‘Some account of Sir Audley Mervyn’, R. Hist. Soc. Trans., iii (1874), 437). When the chairman of the general convention became ill during the second session, Mervyn was chosen as deputy. He received a grant of about 1250 acres in Garristown in north Dublin and was appointed prime serjeant on 21 March 1661.
He was returned to parliament for Tyrone in May 1661, when his eldest son, Henry, was returned for Agher. On May 8, the commons rejected the royal nominee for the speakership, Sir William Domville (qv), in favour of Mervyn after a debate in which Domville's alleged sympathy for catholics and Mervyn's association with Scottish presbyterians featured prominently. In a speech of acceptance adorned with copious Latin quotations and scriptural texts, Mervyn sought to allay suspicions of his orthodoxy and extolled Charles, in the words of a text greatly favoured by protestant parliamentarians, for having given Ireland governors ‘that are bone of our bone and flesh of our flesh’ (Commons' jn., Ire., i, 392). On 13 July he was chosen as a member of a parliamentary commission sent to England with instructions to seek to keep the declaration of 30 November inviolable, and it was not until 1 May 1662 that he resumed the speakership. In February 1663 he acted as spokesman for the commons in its opposition to the proposed bill of explanation and in its demand that the court of claims should tighten its interpretation of innocence and loosen its criteria for the admission of evidence. On 13 February, in a lengthy address to Ormond, Mervyn maintained that the decisions of the court were undermining both religion and the act of settlement, which he described as ‘Magna Charta Hiberniae’ (Commons' jn., Ire., i, 618), and asked that new rules of procedure be prescribed in accordance with parliament's wishes. The speech annoyed the government and angered the king and an effort was made to prevent its publication, but it appeared in both Dublin and London during March. The commons signified its approval of Mervyn's performance by requesting that he be rewarded for his services and loss of earnings. Ormond believed that his alarmist oratory had helped to promote the 1663 plot and the request was ignored. It was repeated more than once, most notably on 30 July 1666 in the last days of the parliament, when the appropriate sum was calculated at £6,000, but payment was delayed till 1667, when the commons overcame official inaction by tacking it on to a supply bill.
Mervyn returned to legal practice after parliament was dissolved and appeared before the second court of claims on behalf of suitors against the estate of the duke of York (qv). He died on 24 October 1675 and was buried in St Werburgh's, Dublin. He was survived by his heir Henry, two sons and a daughter by his second wife, Martha Clotworthy, niece of Sir John (qv), 1st Viscount Massereene, and his third wife, Olivia, daughter of Richard Coote, 1st earl of Collooney.
The pompous pedantry of Mervyn's published utterances, already an object of amusement in the next century, has distracted attention from what he said and did. He was a committed Irish parliamentarian whose claims for Irish constitutional autonomy in 1641 went further than the better known Argument of Patrick Darcy (qv); who was alone in objecting to the constitutional aspects of the Solemn League and Covenant; and whose conduct as speaker of the restoration parliament testified to his radical conviction that his duty was to the house and to the ‘English interest’ rather than to the sovereign.