Leslie, Henry (1580–1661), Church of Ireland bishop of Down and Connor, was born in Scotland at Leslie, Fife, the third son of James Leslie and his third wife, Agnes Somerville. He went to St Andrews University, where he obtained an MA and a DD. In 1614 he emigrated to the recently established plantation in Ulster, where he was ordained deacon and priest on 8 April 1617. He gained a number of increasingly valuable benefices from increasingly important patrons: under his relative, Robert Echlin (qv), bishop of Down and Connor, he was appointed to the prebend of Connor and the rectory of Muckamore (Connor) on 19 June 1619; by 1620 he had come to the notice of Christopher Hampton (qv), archbishop of Armagh, who saw one of his primary tasks in Ireland as the suppression of protestant nonconformity. Leslie became Hampton's chaplain and was appointed rector of St Peter's in Drogheda – in effect the Armagh pro-cathedral. It was Hampton who chose Leslie to preach on 9 June 1622 at Drogheda before the royal commissioners, sent over from England to conduct a detailed investigation of the Irish government and church. The sermon, published as A treatise tending to unitie (1623), is notable for its endorsement of Augustine's use of force against the Donatists, and Leslie's application of the model to official policy towards Irish catholics, and for its complaint that the Irish church was being starved of resources by rapacious landlords. In 1624 he was granted the rectories of Arboe and Clonoe (Armagh) by TCD.
In 1625 Leslie found favour in higher quarters, preaching before Charles I at Windsor, and being rewarded immediately with a royal chaplaincy and later with the deanery of Down (presented 20 May 1627, installed 10 April 1628). This marked a decisive turn in Leslie's career. Although Down had a large Scots settler population, the Church of Ireland there suffered from two serious problems: much church property had ended up in the hands of the planters, depriving clergy of income; and faced with the consequent difficulty in securing clergy, Echlin allowed some Scots presbyterians to serve as ministers in the Church of Ireland. Leslie, like his mentor, Archbishop Hampton, was horrified by this laxity and particularly concerned about the dangers such ‘enthusiasm’ posed to the ecclesiastical establishment. He set out to recover alienated property for the deanery and to stamp out nonconformity in Down. He gained a commission in 1628 to restore alienated properties to the deanery, and succeeded in substantially increasing its value. And he set out to put pressure on Echlin to remove the presbyterian clergy by alerting the authorities in Dublin, Scotland, and England to the extent of their nonconformity. As early as 1629 he had formed an alliance with the bishop of London, William Laud, the rising star of the Church of England, who shared Leslie's twin agenda of restoring the church's finances and removing puritans and presbyterians. In 1632 Leslie's pressure finally told, and Echlin was forced to suspend four Scots ministers. Given the lack of disciplinary provision in the Church of Ireland, however, it proved impossible to tackle the broader problem of nonconformity among the protestant population of Down, who, inspired by the preaching of the presbyterians, had embarked on a full-scale popular evangelical revival, with massive open-air sermons and communions.
Only with the arrival in Ireland in 1633 of Laud's close allies, Lord Deputy Thomas Wentworth (qv), later earl of Strafford, and John Bramhall (qv), was Leslie finally given the power to act. New disciplinary canons were passed in Church of Ireland convocation in 1634, and, in 1635, having turned down the lesser dioceses of Ferns and Leighlin, Leslie was made bishop of Down and Connor (nominated 8 August, consecrated 4 October by Archbishop James Ussher (qv)). Leslie's policies as bishop were little different from those he had followed as dean: the difference was that he now had considerably greater power to enforce his will. With the backing of Wentworth and Bramhall, he set about restoring the finances of the see, regaining land from local landlords and improving its income from £300 to £1,000 by 1641. He also moved decisively against Scots clergy. In August 1636 Bramhall and Leslie held a visitation of Down and Connor and engaged in a public debate with the presbyterian clergy over the issue of kneeling at communion. Subsequently, through suspension and deprivation, Leslie drove the nonconformists out of his dioceses, most of them returning to Scotland. It was, however, a major struggle. In February 1637 Leslie had to procure a warrant from Wentworth allowing him to arrest such people as refused to perform what he had ordered, an exercise in arbitrary government that formed part of the evidence against Strafford at his treason trial. In a visitation sermon preached at Lisnagarvey on 26 September 1638, Leslie not only attacked the Scottish covenant, but also lamented the continuing popularity of the presbyterian ministers among their parishioners and the ‘generall nonconformity’ of clergy and laity ‘and disobedience unto the orders of this church’.
Leslie's concerns over the covenant and the link between presbyterianism and rebellion were, of course, fully justified by the events of the later 1630s, as determined opposition from Scotland led to the recall of the English parliament and the collapse of Wentworth's regime in Ireland. In 1641 a petition against Leslie was presented to the Irish parliament, and in October he was attacked in the Irish rising and forced to flee to England, losing, he claimed, goods and income to the value of £8,000. Energetic and committed as always, Leslie threw himself into the fray on the royalist side, preaching before the royalist parliament assembled at Oxford on 8 March 1644, and again on 27 March, the anniversary of Charles's accession, defending divine right monarchy and attacking ‘the horrible deformitie of this rebellion’ (The blessing of Judah explained (1644), 38). By 1645 Leslie was back in Ireland, defending the Church of Ireland, but he soon returned to England. After the execution of Charles in 1649 he went into exile, preaching in June of that year before Charles's son at Breda in the Netherlands. Some time in the early 1650s Leslie returned again to Ireland and was given a pension of £120 per annum by the Cromwellian government. He had not, however, changed his views: in 1659 he preached against the presbyterian habit of extempore prayer, a sermon published the following year as A discourse of praying with the spirit and with the understanding.
On the restoration of the monarchy in 1660 Leslie was rewarded with the see of Meath (nominated 3 August, letters patent 19 January 1661), but by then he was ‘sunk under the burthen of old age’ (Ware, Works, i, 158) and he died at Dublin 7 April 1661; he was buried at Christ Church cathedral on 10 April. Leslie married Jane Swinton and had three sons, Robert Leslie (qv), later bishop of Dromore, and James and William, who served as officers in the royal army during the English civil war, and two daughters. From him were descended the Leslies of Co. Monaghan.