Joe was known for his comment. “I was born in a united Ireland, I want to die in a united Ireland”.

In May 1920, Cahill was born in Divis Street in west Belfast where his parents had been neighbours with Irish revolutionary James Connolly.

Cahill was the first child in a family of thirteen siblings born to Joesph and Joesphine Cahill. Cahill was educated at primary level at St. Mary’s Christian Brothers Primary School at Barrack Street. Cahill’s father was a printer by trade and an Irish republican who was a former member of the Irish National Volunteers and would produce Irish republican related material at his print shop. At the age of fourteen Cahill left school to assist in the printshop after his father had become ill.

At the age of eighteen, Cahill became a volunteer in the local Clonard based ‘C’ Company of the Belfast Brigade of the Irish Republican Army.

He spent much of his life in fighting British rule in Northern Ireland and was sentenced to death for killing a police officer in the 1940s during the Northern Campaign. However, he had his sentence commuted to life imprisonment due to pressure on the British government by the Irish Free State; the Pope also allegedly called on the Northern Ireland government to grant clemency. Of the six men sentenced to death for the murder of Constable Patrick Murphy of Clowney Street, the Falls Road, Belfast – only one was executed. He was Tom Williams, the leader of the IRA unit that killed Murphy.

Released from prison in 1949 he was then interned following the resumption of an IRA campaign in 1956. His period of internment ended in 1961 but as with other Republican activists during the rest of the 1960s, he grew increasingly disillusioned with the policies and direction of the then leadership. With the outbreak of widespread civil unrest in Northern Ireland in 1969 Cahill joined in efforts to revive the Republican movement and when it split, he helped to establish the Provisional Irish Republican Army (PIRA) in Belfast. It is alleged that he also went onto serve as its Chief of Staff and in 1973 was sentenced to three years by a court in Dublin for attempting to smuggle arms from Libya.

Increasing ill-health saw him released in 1975 and for a time he kept a lower profile whilst beginning to associate himself with Sinn Féin (SF), later serving terms as its General Secretary and Treasurer. As the Republican movement sought to develop its political base in the 1980s he emerged as a key ally of Gerry Adams, then President of Sinn Féin (SF), and supported the efforts to establish SF as a major electoral force. Thus at the 1986 SF Ard Fheis Cahill gave one of the key addresses as to why the party should abandon its traditional policy of not taking its seats in the Dáil. With developments in the ‘Peace Process’ in the early 1990s he again came to prominence when he was given a visa to visit the United States of America just before the declaration of an IRA ceasefire in August 1994.

There is a republican flute band from Glasgow named after Cahill.

Cahill died of natural causes in July 2004, aged 84, in Belfast and is buried in Milltown Cemetery.