Executions were carried out by hanging and firing squads, after which the bodies of the dead were taken down from the gallows and buried within the prison grounds in unmarked graves.

[3] After being convicted of murdering a Garda officer, Charlie Kerins, former Chief of Staff to the Anti-Treaty IRA, was hanged at Mountjoy Prison on 1 December 1944.

On 14 May 1921, an IRA team led by Paddy Daly and Emmet Dalton mounted an attempt to rescue Sean McEoin from the prison.

The Fenian poet, author of the popular song "Rising of the Moon", John Keegan 'Leo' Casey was imprisoned here during the 1860s; subsequently in the 20th century, playwright and IRA activist Brendan Behan was also gaoled within.

On 31 October 1973, it was the scene of a spectacular escape by a hijacked helicopter by three Provisional Irish Republican Army prisoners, Kevin Mallon, Seamus Twomey and Joe B.

[citation needed] In August 2006, prisoners who were normally separated from the rest of the population for safety were mixed together for a night with mentally ill inmate Stephen Egan.

Prisoner Gary Douche was killed by Egan who was found not guilty of murder due to a lack of responsibility.

[11] Facilities in the prison include gymnasiums, computer classes, carpentry, masonry and a wide variety of school activities such as music, drama and cookery.

[1][11] The Controlled Behavioural Unit, known as the CBU or the Block, is used for unruly prisoners or those on punishment and is located in the 'C' Base, underneath the C wing.

[16] The schizophrenic French surrealist playwright Antonin Artaud was briefly detained in Mountjoy before his deportation from Ireland as "a destitute and undesirable alien".

After a protest of starvation, he was transferred across the street to the Mater Misericordiae Hospital on 25 September 1916 where he died a few hours after arrival.

Peadar O'Donnell, IRA Commander of the 2nd Northern Division, was imprisoned in Mountjoy Gaol and the Curragh.

O'Donnell's prison experience and eventual escape in March 1924 are described in his 1932 memoir The Gates Flew Open.