May 25th, 1921: How burning the Custom House made Ireland ungovernable by the British

The Dublin landmark was the ‘administrative heart of the British civil service machine’ in Ireland

The Custom House in Dublin was the last symbol of British civil administration in Ireland. The aim of the republicans was to make the country ungovernable. In this they were quite successful.

As early as 1918, in response to the threat of conscription, Dick McKee, O/C (officer commanding) of the Dublin brigade, suggested they attack the building. McKee again put forward his plan to IRA general headquarters in early 1920 but GHQ had a much bigger operation in mind: to destroy the local tax offices around the country.

The IRA successfully carried out these attacks on the night of April 3rd-4th, 1920, thus leaving the only copies of the income tax records in one place: the Custom House. It was not a matter of if the Custom House was to be attacked, but when.

Éamon de Valera returned from his fundraising tour in the United States in December 1920. He had seen how the international media was portraying events in Ireland. Oscar Traynor, O/C of the Dublin brigade of the IRA, recalled in his BMH witness statement: "He [De Valera] made it clear that something in the nature of a big action in Dublin was necessary in order to bring public opinion abroad to bear on the question of Ireland's case."


De Valera suggested two possible targets, Beggars Bush barracks, which was the headquarters of the auxiliaries, or the Custom House, “the administrative heart of the British Civil Service machine in this country”.

Traynor advised that they should attack the Custom House, which held all local-government records, including all the tax files for Ireland. Commandant Michael Kelly, writing about the operation in 1942, stated that if the operation was a success "its destruction would reduce the most important branch of British civil government in Ireland to virtual impotence and would, in addition, inflict on her a financial loss of about two million pounds".


The operation was planned over three months. It would involve sections of all of the battalions of the Dublin brigade of the IRA. Surveillance was carried out very easily, by simply carrying official-looking envelopes; Oscar Traynor was able to walk freely through the building. Plans came from a friendly contact in the Board of Works. Intelligence came from a number of IRA men who worked in the building.

Harry Colley was one such person. He observed that for the operation to be any way successful, they needed to destroy the will room, which was on the ground floor in the middle of the building, under the dome. In his witness statement, Colley stated: "this was the only combustible part of the building capable of forming a large fire".

Tom Ennis, O/C of the 2nd battalion, was in charge of the operation. His men would carry out the assault inside assisted by members of the squad and active service unit (ASU), with men from the other battalions providing cover. Traynor planned to erect barricades near the military barracks to delay any troops that might arrive. It was estimated that at least 120 men would be needed for the attack, but new research has shown that close to 300 men and a number of women were involved.

Michael Collins did not favour Traynor’s plan to isolate the barracks or the number of men required as he feared they could be lost. A compromise was reached; volunteers would be on duty in the immediate vicinity of the Custom House. Writing in 1942, Comdt Michael Kelly stated that De Valera’s response to this was “that if these 120 men were lost and the job accomplished, the sacrifice would be well justified”.

The fire brigade, whose members included both IRA and ICA, was vital in providing information on the best way to burn such a large building. The operation was to last 25 minutes. Each man would have six rounds of ammunition.

Tins of paraffin

On the morning of May 25th, the volunteers were ordered to meet at specified locations in and around the Custom House. At 12.55pm, Ennis and his men, assisted by the squad and ASU, entered the building, each carrying tins of paraffin. All the other battalions, including the ASU, took up positions in the surrounding area and occupied the fire stations around the city. As the volunteers entered the building, the 5th battalion (engineers) cut the communications from the Custom House.

The volunteers gathered the staff and brought them to the central hall to be supervised by the ASU and the squad. Once the rooms were cleared they prepared to set them alight. When all the rooms were ready, Tom Ennis, with one whistle blast, would signal that the rooms were to be fired. Once done, two whistle blasts would indicate the completion of the job and evacuation.

Daniel McAleese, an employee in the Custom House recalled: “Several young men passed us carrying tins of petrol. One of the leaders announced that the Custom House was being set on fire and warned us against causing any commotion.”

However, word got to the military that the Custom House was being attacked and a party of auxiliaries was dispatched from Dublin Castle. The volunteers had been told that they were not to open fire first. Some volunteers, surprised at seeing the military, opened fire as the auxiliaries came by Liberty Hall.

On hearing the gunshots, the men inside opened fire. In the confusion the blast of a whistle was heard, yet not all of the rooms were ready. The men were ordered to finish their task, causing a delay of a few minutes, but the building was set alight.

As the fire began to take hold, panic set in among the crowd. Calls flooded into the city’s fire stations that the Custom House was on fire. All calls were answered and the people were reassured that help was on the way. But no help was coming; the fire stations were in the hands of the IRA.

With every round of ammunition spent, the order to evacuate was given. The volunteers were ordered to dump arms and mix in with the crowd. The majority did this; others decided to take their chance to try to escape.

Traynor and Capt Paddy Daly were observing the situation outside when they came under fire from the auxiliaries. Volunteer Dan Head threw a bomb at the lorry. Head was shot and killed, but his actions saved the lives of Traynor and Daly. Ennis was the last to leave the burning building. He made a dash from a side gate to a laneway opposite. He was hit twice but managed to get to safety.

Those who had mixed with the staff were gathered outside. Each staff member was identified and led away; those left were searched by the auxiliaries and questioned.

Against a backdrop of the Custom House engulfed in fire, those who were in custody were taken away. Most were brought to Arbour Hill, others were taken to Mountjoy Gaol and Dublin Castle, as Christopher Fitzsimons remembered in his witness statement: "We were segregated on the quayside and taken to Dublin Castle. We were interrogated at the castle for three days and suffered pretty severe handling from the auxiliaries."

After some weeks the majority were transferred to Kilmainham Gaol. Despite their losses, five dead and more than 100 captured, as well as many guns lost, in the days and weeks that followed the Dublin Brigade carried on the fight.

International attention

News of the day’s events raced around the world, focusing international attention on the situation in Ireland, as De Valera had intended. Some, seeing the losses suffered by the IRA, said the operation had been a failure. Others, including those who had taken part, saw beyond that to the crippling blow that had been delivered to the British administration in Ireland. The only criticism the volunteers had about the operation was that those outside had been too close to provide effective cover. If Collins had not insisted on Traynor changing that part of the plan, the military would have been delayed.

Thousands of records essential for running the country were lost. The success of destroying such documents was not just down to the IRA but also the Dublin fire brigade. It was their task to try to save the building. However they did the opposite. Michael Rogers, fireman and IRA man, recalled years later that on entering the building he and others had the building at their mercy and actually spread the fire. The Custom House burned for days.

Sadly, nine people died: five volunteers and four civilians. It was never the intention that anyone should die that day. The volunteers killed were Dan Head, Seán Doyle, the brothers Patrick and Stephen O'Reilly and Edward Dorins. The civilians killed were John Byrne, James Connolly, caretaker Francis Davis and Mahon Lawless.

Later, many claims were made that the operation had been a disaster, and that the IRA had been wiped out, but that was not the case. The aim of this operation was to bring international attention on Ireland; in that it had been successful. It was carried out to make Ireland ungovernable; that objective had been achieved. Despite having their ranks depleted and losing a number of weapons, the IRA adapted their tactics very quickly and continued the war, thus calling the bluff of the British government, and within weeks negotiations to end hostilities began.

Historian Liz Gillis is the author of six books, including Women of the Irish Revolution, The Hales Brothers and the Irish Revolution and May 25: the Burning of the Custom House 1921. She co-wrote We Were There: 77 Women of the Easter Rising