Leslie, Charles (1650–1722), non-juring clergyman and controversialist, was born 17 July 1650 in Glaslough, Co. Monaghan, sixth and second surviving son of John Leslie (qv), DD, bishop of the Isles, Raphoe, and later Clogher, and his wife Katherine, daughter of Alexander Cunningham, dean of Raphoe. Educated at Mr Dunbar's grammar school in Enniskillen, Co. Fermanagh, he entered TCD as a fellow-commoner (5 August 1664); he graduated MA in 1673. Having studied common law for some time at the Middle Temple in London, he finally opted for the church and was ordained in 1680 by Dr William Sheridan (qv) bishop of Cloyne. He returned to his native Monaghan to take up residence with his older brother John, dean of the neighbouring parish of Donogh. He also served as a deacon in Cloyne and a priest in the diocese of Kilmore until 13 July 1686, when he became chancellor of the cathedral of Connor, largely through the influence of the lord lieutenant, Clarendon (qv). Shortly afterwards he became embroiled in a public religious disputation in Monaghan and Tynan with Patrick Tyrrell (qv), the new Roman catholic bishop of Clogher. As chairman of the quarter sessions he sent for trial a catholic named William Barton for refusing to take the oaths after he had been nominated to the post of high sheriff of Monaghan.
In spite of his zeal for the reformed religion he remained loyal to James II (qv) after the ‘Glorious revolution’ and refused to take the oaths to William III (qv) and Mary. He became one of the handful of Irish non-jurors and the primary evangelist of the English non-juring church. Stripped of the chancellorship of Connor, he went to London, where he acted as chaplain to the earl of Clarendon. Returning to Glaslough in 1691, he embarked on a prolific writing career, publishing a great many theological tracts and a vast number of political papers, a veritable armoury of defence against both the opponents of the established church and the exiled house of Stuart. His writings fill thirteen pages in the BL catalogue.
His first major work An answer to the state of the protestants under the late King James's government (1693) was a stinging rebuttal of Bishop William King (qv) and his State of the protestants of Ireland under the late King James's government (1691). Although it was published anonymously in London, the authorities immediately ascribed it to Leslie, and a subsequent search of his Glaslough study uncovered the manuscript. However, the author had escaped and the government allowed proceedings to drop. From the relative safety of London and undaunted by his first brush with the authorities, Leslie set his sights on an even greater quarry than the evangelist of the ‘perjured’ Irish protestant clergy. In his Gallienus redivivus, or murther will out he laid the blame for the judicial massacre, or ‘DeWitting’, of the MacDonnells of Glencoe (February 1692) squarely at the feet of William III himself. He also turned his fire on the English whig divines. He lambasted the Williamite apologists Gilbert Burnet, bishop of Salisbury, and John Tillotson, archbishop of Canterbury, as Socinians and turncoats, and attacked William Sherlock for deserting the non-juring cause. He turned his formidable pen on quakers, Jews, deists, and dissenters. He locked horns with some of the foremost pamphleteers, religious and political commentators of his day, including William Penn (qv), Daniel Defoe, John Dennis, John Locke, John Asgill (qv), and Benjamin Hoadly.
The English government finally issued a warrant for his arrest in July 1710 and he sought asylum in a house belonging to one Francis Cherry. He continued his relentless attacks on his religious and political opponents. He finally made his escape to Saint-Germain in April 1711, brought the young Stuart claimant (James III) a report on the state of Jacobitism in England, and urged him not to renounce his religion for the throne. He followed his young master to Bar-le-Duc, where he obtained a post in his household and wrote a number of manifestos on the king's behalf, and numerous Jacobite propagandist tracts. After the collapse of the 1715 Jacobite rising in Scotland, Leslie followed James to Avignon, where he acted as chaplain to the protestant members of James's household. He also extracted a promise from the Stuart king that he would maintain the rights and privileges of the Church of England in the event of his restoration. However, when his brother John died, Leslie returned to Glaslough with George I's permission, and took possession of the house and lands there. He was not to enjoy his inheritance for long and died 13 April 1722. He was interred in Glaslough churchyard.
After his ordination in 1680 he married Jane, daughter of Richard Griffiths, dean of Ross; they had three children, Robert, Henry, and Jane. Robert succeeded to his father's estate and was living at Islandbridge, Co. Dublin, at the time of his death. Henry served as a colonel, probably under Lord Peterborough in Spain. The brothers were great friends of Jonathan Swift (qv), who dubbed them ‘Mad Robin’ and ‘Harry the Spaniard’. Charles' daughter, ‘Vinegar Jane’, married the Rev. James Hamilton, rector of Knockbreda. Swift, while professing an abhorrence of Leslie's political persuasions, warmly praised his services to the established church. Dr Johnson declared that he was ‘a reasoner who could not be reasoned against’ (DNB).
A number of collections of Leslie's works have appeared. In 1721 the University of Oxford published his theological works. A seven-volume edition of his works was produced in 1823 and contains a reproduction of a portrait of Leslie at Castle Leslie, Glaslough, painted by Alexis La Belle at Saint-Germain. There is also a print of a portrait of Leslie in the NLI Joly Collection.