Mulcahy, Patrick Anthony (1897–1987), soldier, was born 4 November 1897 at 70 Manor St., Waterford city, third youngest child among two sons and five daughters of Patrick Mulcahy, post office official, and his wife, Elizabeth, daughter of Patrick and Maria Slattery, also of Waterford (and at whose family home they had met when Patrick Mulcahy senior was a lodger). His eldest brother later gained distinction as Gen. Richard Mulcahy (qv). Owing to the mobility of his father's career, Patrick Anthony was educated by the Christian Brothers both at Thurles, Co. Tipperary, and at St Flannan's College, Ennis, Co. Clare. Following his father's example, he entered the post office in 1913 and worked at Ennis as a telegrapher.
He joined the British army in 1915 and served in the first world war as a sapper with the Royal Engineers, initially in England, but in France from January 1917 until the armistice of November 1918. He declined a recommendation for a cadetship in the RAF, was demobilised in January 1919, and returned to the post office in Dublin as a sorting clerk at Amiens St. depot. He joined the IRA (of which his brother Richard was chief of staff) in March 1919, early in the war of independence (1919–21). Consequently dismissed from the post office, he devoted most of his time to the war, first as assistant intelligence officer of the Mid-Clare Brigade, 1st Western Division, transferring in April 1921 to the Tipperary North Brigade, 3rd Southern Division, as brigade signals officer. He accepted the treaty of December 1921 and formally joined the National Army in March 1922.
Appointed to signals and retaining the rank of colonel-commandant, he commanded the Maryborough (Portlaoise) and Curragh Camp signal depots until the civil war began in July, when he moved to 3rd Southern Command until January 1923. He was then promoted to colonel and briefly served in Athlone Command until March, 1923 when he took command of a prototype artillery corps, based at McKee (formerly Marlborough) Barracks in Dublin. Appointed commander of the artillery corps in February 1924, he reverted in April to the rank of major in the postwar army rationalisation process. His title became ‘director of artillery’ from November 1931 and he was officer commanding the air corps from September 1936, having served in an acting capacity since June 1935. He gained some flying experience but was chiefly an administrative commander. He was promoted to colonel in April 1939.
After the greatest danger of invasion during the Emergency of 1939–45 had passed, he returned in December 1942 to his earlier role as director of artillery, where he remained until December 1948. Mulcahy's subsequent career was a steady rise in senior command and general staff appointments: OC Western Command January–October 1949, quartermaster-general until January 1952, OC Eastern Command until January 1955, when he was promoted to major-general and appointed chief of staff, the same position his older brother had occupied at the foundation of the state. He oversaw the first Irish United Nations peacekeeping missions, beginning with Lebanon in 1958 (where his grandson Patrick later served), establishing a familiar and benevolent Irish international presence.
Retiring on New Year's day 1960 with the rank of lieutenant-general, Mulcahy indulged his passion for horses and became secretary of the Turf Club committee, which planned the first Irish Sweeps Derby in 1962. He was also the club's chief steward, and was manager and director, respectively, of Baldoyle and Leopardstown racecourses. His squash interest had earned him the presidency of the Irish Squash Racquets Association as early as 1938. His last home was at 6 Avondale Road, Killiney, Co. Dublin; he had lived both in and out of barracks throughout his career. His religious faith, Roman Catholic coloured by ancestral quakerism on his father's side, was a strong family tradition: several close relatives had entered holy orders, including his son Richard (‘Dick’). When he died (16 May 1987), aged 89, at Our Lady's Hospice, Harold's Cross, Dublin, Richard celebrated the funeral mass, prior to burial at Dean's Grange cemetery.
Mulcahy married first (January 1923) Josephine (d. May 1935), daughter of the anti-treaty Sylvester Barrett and his wife Johanna, of Ennis; they had five children. He married secondly (April 1939) Pauline Barrett, Josephine's sister.