O'Hara, Sir Charles (d. 1724), 1st Baron Tyrawley , general, was Irish-born and had a connection with Kean O'Hara of Collooney, Co. Sligo, with whom he corresponded and with whom he shared catholic relations. Neither his parents nor his exact place of origin have been identified, however (though Co. Sligo, Co. Mayo, and even Co. Antrim have been suggested), and his date of birth is doubtful. He first appears as a captain in the regiment of the duke of York (later James II (qv)) in 1678, and was in Holland in the regiment of the earl of Ossory (qv) in 1679. He was a captain in the 1st Foot Guards in 1687, and was promoted colonel of foot (1689), brigadier-general (1695), and lieutenant-general (1704). He served (1691–6) in Flanders, where he was gravely wounded at Landen in 1693.
He was for a time a protégé of the duke of Ormond (qv), who nonetheless, during the expedition to Cadiz in 1702, had him arrested on a charge of looting; he was acquitted by the subsequent court martial. During service in Spain he distinguished himself in the defence of Guadalajara in 1706. He took part in a divided conference of generals in 1707 when he, with other whig generals, was opposed by the earl of Peterborough, a tory. The ensuing battle of Almanza was a severe defeat for the allies, and recriminations followed. These were revived in the wake of another allied defeat, at Brihuega (December 1710). The tories were by now dominant in English politics, and initiated an inquiry in the house of lords into the earlier defeat, which was associated with the whigs. Tyrawley was one of those who gave evidence to the house in January 1711. A resolution was passed condemning the counsels of the whig generals, including Tyrawley, but the affair was otherwise inconclusive.
He was knighted (1689); created Baron Tyrawley in the Irish peerage (1707); and appointed to the Irish privy council (1710). His whig connections stood him in good stead at the accession of King George: in 1714 he was reappointed to the Irish privy council, promoted full general, and appointed commander-in-chief of the forces in Ireland, a post he retained till 1720. He was also elected a governor of the Royal Hospital, Kilmainham, in 1714. The first lord lieutenant of George's reign, the earl of Sunderland, used Tyrawley as an envoy in negotiations with the Irish whigs during 1714–15. He died 8 June 1724 in Dublin.
He married (a. 1682) Frances, daughter of Gervase Rouse of Rous Lench, Worcester; they had a daughter and a son, James O'Hara (1690–1773), who served with his father in Spain, and succeeded him as colonel of the 7th Regiment of Foot in 1713. James had tory sympathies, for which reason his father declined to support his attempt to win a seat in the Irish house of commons for Co. Mayo in 1715. He was created Baron Kilmaine in the Irish peerage in 1723, succeeded his father as Baron Tyrawley in 1724, and was made a privy councillor of Ireland in the same year. He held numerous high military and diplomatic appointments during a long career, but died without legitimate children in 1773, when his titles became extinct. An illegitimate son, Charles (1740?–1802), was also a general; he served in America and was governor of Gibraltar from 1795 to his death. There are papers relating to the O'Haras in the NLI and in the BL (Tyrawley, Blenheim, and Ellis MSS).