Hughes was born into an Irish Nationalist Catholic family from the Lower Falls area of Belfast, Northern Ireland.

Hughes described his normal day during that period as "you would have had a call house [a safe meeting place] and you might have robbed a bank in the morning, done a float [gone out in a car looking for a British soldier] in the afternoon, stuck a bomb and a booby trap out after that, and then maybe had a gun battle or two later that night.

"[7] After the IRA-British truce of 1972 broke down in July, Hughes was an IRA commander during the Battle of Lenadoon, which quickly spread to other parts of Belfast.

[10]On 19 July 1973, Hughes was arrested on the Falls Road along with Gerry Adams (later President of Sinn Féin between 1983 and 2018) and Tom Cahill.

They were interrogated for more than twelve hours at the Springfield Road Royal Ulster Constabulary (RUC) barracks and later at Castlereagh, before being transported to Long Kesh.

After ten days he returned to Belfast after assuming a new identity, becoming a travelling toy salesman named "Arthur McAllister".

For five months, Hughes lived in Myrtlefield Park near Malone Road, and was believed to be the new O/C of the IRA in Belfast following the arrest of Ivor Bell in February.

Against the wishes of the IRA Army Council, on 27 October 1980, Hughes along with six other republican prisoners, including Tom McFeely, John Nixon, Sean McKenna, Tommy McKearney and Raymond McCartney, refused food and started a hunger strike.

[22] In October 2006, Hughes was pictured on the front page of the Irish News wearing an eye patch after undergoing an operation to save his sight, which had been badly damaged due to his hunger strike.

[4][24] In accordance with Hughes’s wishes, his ashes were buried or scattered in three places in Ireland: the grave of his parents; the ruins of his grandfather’s home in the Cooley mountains in County Louth, and at the D Company memorial on the Falls Road – but not at the Provisional plot in Milltown cemetery.

In a recording released in 2013 after his death, Hughes named Gerry Adams as ordering the murder and secret burial of Jean McConville during the IRA's campaign in Belfast in 1972.