Justin McCarthy , Viscount Mountcashel Justin McCarthy , Viscount Mountcashel ( died 1 July 1694 ) was a Jacobite general in the Williamite War in Ireland , and a personal friend of James II . Background . McCarthy was the younger son of Donough MacCarty , 1st Earl of Clancarty , from the MacCarthy of Muskerry dynasty who had lands in County Desmond . His mother was Lady Eleanor Butler , sister of the 1st Duke of Ormonde . The family had had their property confiscated under the Cromwellian regime , but restored in the restoration . Justin McCarthy was made Viscount Mountcashel with the subsidiary title of Baron Castleinch on 1 May 1689 and became a Lieutenant - General . Justin was born about 1643 , and seems to have grown up mainly in France . He became a professional soldier , and showed great skill , but poor eyesight hampered his career . He entered the French army in 1671 , and then transferred to the Duke of Monmouth ' s regiment , then in French pay , and served against the Dutch . He came to England in 1678 and was befriended by the future James II , who generally chose soldiers , especially Irishmen , as his companions . Charles II decided to use him for service in Ireland , and made him a colonel in Sir Thomas Dongan ' s regiment . On the outbreak of the Popish Plot , however , the discovery of MacCarthy ' s presence at Whitehall caused uproar : he fled the country , and the Secretary of State , Sir Joseph Williamson , who had issued his commission , was sent to the Tower of London . Family disputes . By 1683 he was at Court again , and his growing influence is shown by the marriage he arranged for his nephew Donough MacCarthy , 4th Earl of Clancarty . The 3rd Earl had died in 1676 , leaving his young son in the care of his widow Elizabeth FitzGerald , daughter of the Earl of Kildare , " a fierce Protestant isolated in a Catholic family " . She placed her son in the care of John Fell , Bishop of Oxford , for a Protestant education . Justin was determined to have the final word on the young earl ' s marriage and religion , and persuaded the King to invite him to Court for Christmas . Here Donough , at sixteen , was married to Elizabeth Spencer , daughter of Robert Spencer , 2nd Earl of Sunderland , who was two years younger . The marriage was a failure , and Sunderland ' s biographer remarked that it left a stain on the reputation of all those who ruined the lives of two young people , without any obvious gain . Under James II . Under the Catholic James , MacCarthy became both Major General and a member of the Privy Council of Ireland . He quarreled with the Lord Lieutenant , the Earl of Clarendon , and probably worked to secure his recall . In 1689 he took Castlemartyr and Bandon for James ; at Bandon there was a massacre called " Bloody Monday " , but MacCarthy persuaded the King to issue a general pardon . He met James at his landing at Kinsale , and was commanded to raise seven regiments . He sat in the Irish House of Lords in the Parliament of 1689 . With 3 , 000 men he advanced from Dublin towards Enniskillen , which with Derry was the remaining resistance to James II . He was met by 2 , 000 Protestant ' Inniskillingers ' at the Battle of Newtownbutler on 31 July 1689 . Mountcashel ' s forces were routed ; he was wounded , then captured . Allowed out on parole he broke parole and escaped to Dublin ; Schomberg remarked that he had thought Maccarthy was a man of honour but expected no better from an Irishman . He went into exile in France and commanded the first Irish Brigade of Louis XIV . His later career was hampered by his near - blindness . He died at Barège in 1694 and was buried there . Family . He married Lady Arabella Wentworth , daughter of Thomas Wentworth , 1st Earl of Strafford , who was many years older than himself ; they had no children . At his death he tried to leave his property to a cousin , but much of it seems to have come to Catherine , sister of the 4th earl . Her husband , Paul Davys , had the title Viscount Mountcashel revived .