Jeremiah Joseph “Ginger” O’Connell, Irish revolutionary, active in the Irish War of Independence, and later a senior officer in the Defence Forces, is born in Ballina, County Mayo, on December 21, 1887.

O’Connell is born to Jeremiah Ambrose and Winifred O’Connell. He is nicknamed “Ginger” because of his red hair. His father is a national school inspector, so the family lives in Sligo, Derry, Longford and Belfast, and he attends a succession of primary schools. He studies at University College Dublin (UCD) where he receives a BA and a first class MA. He is a member of the Literary and Historical Society at UCD, and has an interest in boxing.

O’Connell is living in Cavan with his father, his sister Mary Margaret, his brother John Aloysius and two servants, Mary Burke and Rose Anne O’Reilly, at the time of the 1911 census, when he is 23. He is working as a Solicitor’s Apprentice, can read and write as well as speak both English and Irish, and is single. His mother is not living as it is recorded that his father is a widower.

O’Connell spends some time in the United States Army, serving with the 69th New York Infantry Regiment between 1912 and 1914. He returns to Ireland in 1914 and joins the Irish Volunteers, becoming Chief of Inspection in 1915. He travels the country organising volunteer corps, as well as contributing to the Irish Volunteer’s journal and delivering lectures on military tactics to both the Volunteers and Fianna Éireann. He also delivers a series of lectures about the famous Irish battles to the Gaelic League in Dublin. He is not a member of the Irish Republican Brotherhood (IRB) as he believes that soldiers should not be a part of secret societies.

At the time the 1916 Easter Rising, O’Connell is operating in Dublin under instruction from Joseph Plunkett. He is dispatched to Cork by Eoin MacNeill to try to prevent the Rising. Following the Rising, he is arrested and held in Frongoch internment camp from April to July 1916. In 1918 he is again arrested and interned, spending time in Wandsworth Prison with Arthur Griffith for the alleged involvement in the fabricated German Plot.

During the Irish War of Independence, O’Connell is a member of the Irish Republican Army (IRA) headquarters staff, as Assistant Director of Training and, after the killing of Dick McKee in 1920, as Director of Training. He coordinates, and is the principal lecturer, for a training course for military officers. The course is run clandestinely in the premises of the Topographical Society on Gardiner Street in Dublin. A sympathetic doorkeeper allows the group in at night when the society is not present. Topics delivered by O’Connell include tactics, ordinance and engineering.

In the IRA split after Dáil Éireann ratifies the Anglo-Irish Treaty, O’Connell takes the pro-Treaty side. He is made Deputy Chief of Staff in the National Army. On June 26, 1922, he is kidnapped by anti-treaty forces in reprisal for the arrest of an anti-treaty officer. His kidnapping is a precipitating factor in the formal outbreak of the Irish Civil War, when government pro-treaty forces two days later attack anti-treaty forces occupying the Four Courts. He survives the fighting and spends the rest of the civil war as General Officer Commanding the Curragh Command.

Following the Irish Civil War, the National Army is reorganised, and as part of that O’Connell is demoted from general to colonel. He subsequently holds a variety of positions: chief lecturer in the army school of instruction (1924–1929); director of no. 2 (intelligence) bureau (1929–1932); OC Irish Army Equitation School (March–June 1932); quartermaster-general (1932–1935) and director of the military archives (1935–1944). He also publishes articles on Irish and foreign military history and tactics in his time as a military historian. He marries Gertrude McGilligan, and they have two children together – one son and one daughter.

O’Connell dies of a heart attack at the age of 56 on February 19, 1944.