O'Kelly, Charles (1621–95), Jacobite army officer and writer, was born at Screen castle, Co. Galway, eldest son of John O'Kelly (d. 1674), 8th lord of the manor of Screen, and Isma, daughter of Sir William Hill of Ballybeg, Co. Carlow. He received his education at St Omer in the Netherlands, where he acquired a proficiency in Latin, Greek, French, and Flemish. Summoned home on the outbreak of the rebellion of 1641 he distinguished himself in the royalist cause under the command of James Butler (qv), marquess of Ormond. After the final collapse of the royalists he sailed for Spain with 2,000 Irish soldiers to enter the service of the exiled Charles II. He joined the king in France, but following the alliance of 1657 between Oliver Cromwell (qv) and Cardinal Mazarin, which led the French to expel the exiled Stuarts and their followers from their territory, O'Kelly returned to Spain.
He returned to his native land, via England, on the restoration of Charles II in 1660 and later succeeded to the family estates on the death of his father in 1674. He led an inconspicious existence until in his sixties he again rallied to the Stuart cause in support of James II (qv). In 1686 he became one of the twenty-four new burgesses of the restored and remodelled corporation of Athlone. He sat as MP for Roscommon in the patriot parliament of 1689. He raised a regiment of infantry for James's Irish army, which he commanded himself with his brother John as lieutenant general; although it was later disbanded he continued to serve on the army staff with the rank of colonel. After abandoning Sligo in August 1689, Patrick Sarsfield (qv) drew back to Roscommon and appointed O'Kelly to command a local force against the incursions of the marauding Enniskilliners from Ulster, while Sarsfield travelled to Dublin to report on events. O'Kelly's force was routed by a group of rebel infantry and cavalry led by Thomas Lloyd in the vicinity of Boyle, Co. Roscommon, on 20 September. Although O'Kelly escaped, Lloyd intercepted his portmanteau which contained a letter to Sarsfield, which he forwarded to the Williamite commander, the duke of Schomberg (qv).
O'Kelly was made high sheriff of Co. Roscommon in 1690 and appears to have remained there until the following year. He was one of the garrison on Boffin island at the time of its capitulation on 19–20 August 1691. In spite of this, he again took command of a strong Jacobite force at Lough Glin, Co. Sligo, which he was forced to surrender on 9 September 1691. He then proceeded to the besieged citadel of Limerick. In mid-September O'Kelly warned Sarsfield and the Jacobite leadership that Brigadier Robert Clifford (qv), who was in command of the Jacobite troops defending the city on the Clare bank of the Shannon against the Williamite commander Ginkel (qv), was neither trustworthy nor competent. But owing to dissension among senior Jacobite officers, Clifford was left in command of 1,500 horse and O'Kelly's suspicions were vindicated: the Williamites were able to construct a bridge across the river and take the Clare bank. After a ceasefire was declared some days later, the terms of the final surrender of Limerick were to be agreed, and it was proposed by James Lynch (qv), the catholic archbishop of Tuam, that O'Kelly should take part in the negotiations. This suggestion was opposed by a faction hostile to the colonel. At the conclusion of the treaty of Limerick, O'Kelly retired to Screen, where he devoted himself to literary and spiritual pursuits.
His best-known work was his Macariae excidium, or, The destruction of Cyprus, which purported to be a translation of a Latin history, but was, in fact, a disguised account of the Jacobite war in Ireland, in which both places and people were given classical names in the allegorical tradition of Dryden's Absalom and Achitophel and John Sergeant's Historical romance. The disgruntled O'Kelly censured James II for his failure to rescind the ‘impious’ laws enacted against the catholic church, and he criticised the ‘revels, gaming and other debauches’ of the Irish Jacobite army, which he claimed contributed to Ireland's downfall. He was particularly critical of the earl of Tyrconnell (qv) and those within the Irish Jacobite polity whom he regarded as too eager to make peace with the Williamite usurper. Similarly, he conveyed the general astonishment among the Jacobite ranks at the speed and ease with which Sarsfield acquiesced in coming to terms with the enemy. Another major work, ‘Mémoires du Colonel Charles O'Kelly de Skryne, sur les guerres d'Irlande de 1641 et suivans, et de 1689 et suivans’, comprising a full and extensive account of the rebellion of 1641 and the Jacobite war, passed down among the French members of the family until it was destroyed during the French revolution.
O'Kelly married Margaret O'Kelly, daughter of Tadhg (or Teigue) O'Kelly of Gallagh, Co. Galway. He died in 1695. His only son, Dennis, served as a captain of horse in the cavalry regiment of Lord Galmoy (qv), and then with Lord Mountcashel (qv) when his forces were routed at Newtownbutler, Co. Fermanagh, by the Enniskilliners. Denis succeeded his father as 10th lord of Screen and retained his Jacobite sympathies. Committed to the Tower of London on 30 July 1722 on suspicion of being a party to the Atterbury plot, he was bailed the following November and discharged on 26 May 1723. He died in 1740.