McKenna, Daniel (1892–1975), army officer and chief of staff, was born 1 December 1892 at Bracareilly, Draperstown, Co. Londonderry, son of Peter McKenna, farmer, and Mary Anne McKenna (née McKenna). He was educated at Lisnamuck national school at Maghera, Co. Londonderry, before attending Rainey preparatory school in Magherafelt, Co. Londonderry. He worked in a wine and spirit business on leaving school, and in 1916 was made manager of a garage in Maghera. He had joined the IRB in 1913, however, and in 1915 joined the Irish Volunteers. Active throughout the war of independence, he served as OC 4th Brigade, 2nd Northern Division, and was later made deputy OC of the 2nd Northern Division.
He was commissioned (7 September 1922) in the new national army with the rank of colonel-commandant and was initially OC Ponsonby Barracks in the Curragh camp. Promoted to colonel (March 1923), he had to take a reduction in rank due to the army reductions in 1924, and was made major. He subsequently served as adjutant of the Claremorris Command and the Southern Command. In July 1929 he was appointed deputy quartermaster-general, and in July 1931 was promoted to colonel for the second time. In November 1931 he was appointed director of supply and transport (1931–5), and also served as a member of the special powers tribunal (1933–4). He was appointed director of cavalry on 4 June 1935, and then again deputy quartermaster-general on 14 April 1939. In July 1939 he was made a member of the special criminal court (1939–40).
There was some surprise when on 29 January 1940 he was promoted to major-general and made chief of staff in succession to Gen. Michael Brennan (qv), as he was far down the list of eligible candidates. This may have been because more senior officers were regarded as compromised by their civil war service, or because McKenna's energy and initiative had impressed Éamon de Valera (qv) some years earlier. McKenna proved to be a forceful and pragmatic chief of staff, and quickly set about attempting to rectify the army's weaknesses. He recognised that many regular officers were too old and lacked drive, and that the scattering of small units throughout the country for reasons of internal security and coastal defence meant that the army was weak almost everywhere. Furthermore, the shortage of automatic weapons, anti-tank guns, and artillery meant that it would be unable to offer any serious resistance to an invading force. During the war a trickle of arms was imported from Britain and McKenna tried to make up the shortfall by initiating the manufacture of munitions and armoured cars at home. After the invasion of France and the Low Countries in May 1940, McKenna convinced de Valera and the minister for defence, Oscar Traynor (qv), that full mobilisation was necessary. Despite the crippling shortage of equipment, the regular army was increased from 13,000 to 41,000 men in March 1941. In January 1941 a Local Defence Force (LDF) of almost 90,000 men was established and the chief of staff worked hard to turn its raw recruits into an integral part of the defence forces.
In May 1941 McKenna was promoted to lieutenant-general, and organised the army into two divisions, one to defend the border, the other to guard the southern ports and coastline. Training was stepped up and, although arduous exercises revealed weaknesses, the army's combat capability was improved. The increased likelihood of a German attack on Ireland led to a secret agreement on military cooperation with Britain, and McKenna quickly established good relations with Gen. Sir Harold E. Franklyn, the British army commander in Northern Ireland, taking him on a tour of Irish military bases in August 1941. McKenna, though, was adamant that any British movement into the south could only occur after Irish forces had first engaged the Germans, and that the Irish army would not be placed under British command.
The war had sharply highlighted the inadequacy of Ireland's defence forces and in March 1945 McKenna outlined proposals for a properly equipped and trained professional army to be supported by substantial reserve forces, and argued that some form of compulsory military service would be required to ensure that in future the country could be defended properly. His views were rejected and after the war the government slashed the defence budget and drastically reduced the size of the defence forces; by May 1946 the regular army amounted to only 9,000 men, scattered throughout the state. During his remaining years as chief of staff McKenna's relations with the Department of Defence were often strained. Promoted to full general on 1 December 1948, he retired on 30 January 1949, and was succeeded by Gen. Liam Archer (qv). He died 11 April 1975, and was buried in Glasnevin cemetery, Dublin.
He married (January 1927) Margaret, née Doherty (d. Dec. 1975); together they had three sons and a daughter.