One hundred years ago today, on 17 November 1922, four members of the anti-Treaty IRA - John Gaffney, James Fisher, Peter Cassidy and Richard Twohig - were shot by firing squad in Kilmainham Gaol in Dublin.
All four had been arrested a few days earlier carrying revolvers on the streets of Dublin.
A new phase had opened in the Civil War.
The Provisional Government had introduced new regulations allowing the National Army to execute anyone outside its ranks found carrying weapons without authorisation.
At the end of September the new set of regulations, the Army Emergency Powers Resolution, was voted through by the Dáil.
Between November and the end of the Civil War in May 1923, a total of 81 prisoners would be executed, most of them rank-and-file members of the anti-Treaty IRA, including several deserters from the National Army.
Out of over 12,000 men taken prisoner in the course of the war, about 1,200 faced trial, and 400 were sentenced to death. Those condemned men not executed had the death sentence hanging over them for the duration of the war.
Government ministers stated that the reason the executions policy was introduced was that the IRA had embarked on a scorched-earth campaign of destruction of every type of facility the new State needed to function, including railways, roads, bridges and waterworks.
It had also targeted the revenue-raising arm of the administration by attacking tax offices and revenue officials.
The government feared that it would run out of money to run the country and conduct the war before the IRA could be defeated, unless there was a radical change in the way the war was fought.
The government believed that if ordinary rank-and-file anti-Treaty IRA men could see people just like themselves being executed instead of just being imprisoned, they would lose heart and give up the struggle.
The execution of the four Volunteers in Kilmainham was soon followed by the shooting of Erskine Childers, a member of the delegation that had signed the Treaty in London, but who was now an implacable opponent of its provisions.
As the pace of executions quickened, the response from the anti-Treaty IRA leadership grew more radical.
'Take them out and shoot them' - Irish State executions
To the list of its enemies to be shot on sight, the IRA Chief of Staff Liam Lynch added the names of all those TDs and ministers that had voted the Emergency Resolution through.
He also declared their homes and property to be fair game.
On 7 December, the day after the Free State formally came into being, two TDs were shot on the streets of Dublin. Sean Hales was killed, Padraic O'Maille was wounded.
The government considered this to be an escalation threatening the foundations of democracy, to add to all the other mortal threats to the future of the country.
Four anti-Treaty IRA officers, who had been in captivity since the fall of the Four Courts in July, were selected for execution.
Rory O'Connor, Liam Mellows, Joe McKelvey and Richard Barret were shot in Mountjoy Jail on the morning of 8 December.
The government officially described the killings of the four men as a "reprisal" for the death of Sean Hales.
This was a recognition by the government that there had been no legal basis on which to sentence the men to death, they had broken no law. They were in custody since before the new Emergency Resolution was adopted, so could not have broken its provisions.
The response of the anti-Treaty IRA was to redouble its attacks on the homes and property of TDs and ministers. Attacks on public buildings and infrastructure increased.
The government ended 1922 by making the new measures even more draconian.
More offences were added to those carrying the death sentence, to include even knowing of the whereabouts of illegal weapons.
More and more cases were not heard by military courts but by committees, which had even fewer protections for the accused.
To maximise the impact of the executions on the IRA rank-and-file, most of the rest of the shootings were carried out in barracks around the country.
Death sentences were passed on many men but not carried out. A new policy was to make those prisoners hostages for the actions of their comrades still at liberty.
At the end of the Civil War, the government passed legislation to retrospectively make the executions policy legal.
Ten years later, as the government prepared to hand over power to Fianna Fáil, which was founded by anti-Treaty Republicans, most of the records relating to the executions were ordered to be destroyed.
