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.