The Custom House in Dublin is occupied and then burned in an operation by the Irish Republican Army (IRA) on May 25, 1921, during the Irish War of Independence. At the time, the Custom House is the headquarters of the Local Government Board for Ireland, an agency of the British administration in Ireland, against which the IRA is fighting in the name of the self-proclaimed Irish Republic. The operation, involving over 100 IRA volunteers, is a propaganda coup for the republicans but a military disaster for the IRA in the Irish capital. A force of British Auxiliaries quickly arrives, and a gun battle erupts. Five IRA volunteers, John Doyle, Edward Dorins, Daniel Head, Captain Patrick and Lieutenant Stephen O’Reilly, are killed, along with three civilians. Approximately 80 volunteers are captured.

The operation is the largest action in Dublin by rebels since the Easter Rising of April 1916.

The Irish War of Independence is a guerrilla campaign by the IRA in support of the Irish Republic. The conflict enters its bloodiest phase in the first six months of 1921. In Dublin, a total of 309 people are killed in the conflict and several hundred more wounded.

Dublin is garrisoned by over 10,000 British troops and 1,600 police including 400 men of the Royal Irish Constabulary (RIC) Auxiliary Division. Most IRA actions in the city consist either of assassinations of selected police, military or administration figures by the Squad, or ambushes on British forces by one of the four Active Service Units (ASU) of the IRA’s Dublin Brigade, together comprising about 100 men. These are usually rapid and fleeting attacks using grenades and handguns, followed by a quick getaway. There are strict orders given to IRA units to avoid prolonged engagements with the better-armed British forces.

However, this policy is reversed after a meeting of the Ministry of Dáil Éireann in May 1921 where the President of the Republic, Éamon de Valera, calls for a spectacular public show of force by the IRA, to reinforce the idea that it is an army representing an Irish government. For this reason, it is decided to attack and burn the Custom House, which, although an important government building, is not defended by the British military. Michael Collins is against the attack but is overruled.

Michael O’Kelly, Lieutenant E Company, 2nd Battalion, Dublin Brigade, recalls plans to “deliver a smashing blow to England.” Two large scale operations – to capture Beggars Bush Barracks, or to destroy the Customs House are initially considered. The Custom House is eventually chosen. IRA member Vincent Byrne says that the operation is “one of many under review.”

In the early afternoon of May 25, 1921, roughly 120 non-uniformed IRA Volunteers begin to gather around the Custom House in groups of two or three. Three quarter of those involved belonged to the 2nd Battalion of the Dublin Brigade under Tom Ennis. Only a minority of them are experienced guerrilla fighters and they are armed only with pistols and a limited amount of ammunition. At 1:00 p.m., they rush the Custom House and overpower the police guard. A lorry pulls up outside the building with tins of petrol and bales of cotton, which are then sprinkled throughout the building. The IRA Volunteers herd all the staff into the main hall. The caretaker of the building, Francis Davis, is shot dead when he tries to call the police.

However, at about 1:10 p.m., a watching policeman notifies British forces and 60 Auxiliaries in three lorries and an armored car quickly arrive on the scene. IRA Volunteers from the 1st, 3rd and 4th battalions are positioned outside the building to stop the enemy from approaching.

Four Auxiliaries are wounded in a gun battle with one of these IRA protection teams outside the building. Other Auxiliaries fire into the building with rifles and Lewis machine guns, exchanging fire with the IRA fighters inside. A number of IRA Volunteers and civilians are killed or wounded by the Auxiliaries. As fighting rages outside, IRA Volunteers inside the building are ordered to set it alight.

The ammunition of the IRA Volunteers quickly runs out and the firefight ends within 30 minutes. Some Volunteers are shot as they try to run away. Tom Ennis, in command of the operation, escapes but is hit twice in the leg. Many others are arrested along with civilians as they come out of the now burning Custom House with their hands up. The Fire Brigade, which had been delayed from responding by other IRA companies in the city, arrives too late to put out the fire.

British military forces composed of units from the Wiltshire Regiment arrive and take over the operation from the Auxiliaries at this point. A total of 111 people are arrested, of whom 70–80 are IRA volunteers.

The Custom House burns for five days and is all but completely destroyed by the fire. With it are destroyed many centuries of local government records. The Irish Bulletin, official gazette of the Irish Republic, reports:

“A detachment of the Dublin Brigade of the Irish Army was ordered to carry out the destruction of the Custom House in accordance with a decision arrived at after due deliberation of the ministry of Dáil Éireann. We in common with the rest of the nation regret the destruction of historical buildings. But the lives of four million people are a more cherished charge than any architectural masterpiece. The Custom House was the seat of an alien tyranny.”

From the republican point of view, the operation is successful for its propaganda value, but it is a heavy blow in terms of the numbers lost, both killed and arrested. Following the operation, the Dublin Brigade and The Squad are amalgamated into the Dublin Guard. However, the operation does not totally impede the IRA’s campaign in Dublin. The Dublin Brigade carries out 107 attacks in the city in May and 93 in June, showing a decline but not a dramatic one.

The memoir of Harry Colley, Adjutant of the Dublin IRA, estimates the numbers in the five Dublin battalions at 1,400 in early 1921.

The armed conflict is brought to an end on July 11, 1921, and negotiations are opened which produces the Anglo-Irish Treaty in December of that year. The Custom House is re-built after the end of the war.

Irish local government records from the 1600s had been brought from rural parts of Ireland to the Custom House for safekeeping, and these are lost in the blaze. At the time, The New York Times subtitles their report on the fire as “Priceless Records Lost.” Some genealogists still lament the loss of these historical records.

(Pictured: The Custom House in flames, taken on May 25, 1921)