Irish Republican Army

The Irish Republican Army (IRA) (Óglaigh na hÉireann ) was an Irish republican revolutionary military organisation. It was descended from the Irish Volunteers, an organisation established on 25 November 1913 that staged the Easter Rising in April 1916. In 1919, the Irish Republic that had been proclaimed during the Easter Rising was formally established by an elected assembly (Dáil Éireann), and the Irish Volunteers were recognised by Dáil Éireann as its legitimate army. Thereafter, the IRA waged a guerrilla campaign against British rule in Ireland in the 1919–21 Irish War of Independence.

Following the signing in 1921 of the Anglo-Irish Treaty, which ended the War of Independence, a split occurred within the IRA. Members who supported the treaty formed the nucleus of the Irish National Army founded by IRA leader Michael Collins. However, much of the IRA was opposed to the treaty. The anti-treaty IRA fought a civil war with their former comrades in 1922–23, with the intention of creating a fully independent all-Ireland republic. Having lost the civil war, this group remained in existence, with the intention of overthrowing both the Irish Free State and Northern Ireland and achieving the Irish Republic proclaimed in 1916.

Origins
Physical force Irish republicanism as an ideology had a long history, from the United Irishmen of the 1798 and 1803 rebellions, to the Young Irelander Rebellion of 1848 and the 1867 rebellion by the Irish Republican Brotherhood. In addition, the methods of the IRA were to some extent inspired by the traditions of militant agrarian Irish secret societies like the Defenders, the Ribbonmen and the supporters of the Irish Land League. The acronym IRA was first used by the IRB organisation in America (also known as the Fenian Brotherhood). This "Irish Republican Army" of the 1860s comprised the American Fenians' paramilitary forces, organised into a number of regiments. Fenian soldiers wearing IRA insignia fought at the Battle of Ridgeway near Buffalo, New York on 2 June 1866. However the term Irish Republican Army in its modern sense was first used in the second decade of the 20th century for the rebel forces of the Irish Volunteers and the Irish Citizen Army during the Easter Rising. It was subsequently, and most commonly, used for those Volunteers who fought a guerrilla campaign in 1919–1921 in support of the Irish Republic declared in 1919.

Background—Home Rule and the Volunteers
The political violence that broke out across Ireland in 1919, and which continued on and off until 1923, had its origins in Irish nationalist demands for Home Rule within the United Kingdom of Great Britain and Ireland, and unionist resistance to those demands.

In 1912 the Liberal government introduced the Third Home Rule Bill into the British Parliament, with the aim of establishing self-government for Ireland within the United Kingdom. The passage of the Bill through Parliament over the next two years was accompanied in Ireland by the formation of first unionist, and then nationalist, mass-membership armed militias: the Ulster Volunteer Force and the Irish Volunteers, respectively.

By May 1914 the Bill had complied with the requirements set down by the Parliament Act 1911, allowing the government to force its enactment over the heads of the unionist-dominated House of Lords. Attempts at reaching some sort of compromise between the conflicting parties meant the Bill still had not received the Royal Assent by the outbreak of the First World War in August 1914. The situation in Ireland had become critical, with the two large militia organisations openly drilling, unionists having illegally imported guns, and the reliability of the British armed forces uncertain.

The outbreak of war in Europe temporarily averted the standoff in Ireland. John Redmond, the leader of the nationalist Irish Parliamentary Party, was prepared to accept British promises to deliver Home Rule, and publicly backed the British war effort. In September, the government finally had the Bill formally enacted, but simultaneously postponed its implementation while the war in Europe continued.

The Irish Volunteers split. The National Volunteers, with over 100,000 members, were prepared to continue under Redmond, and about 20,000 of them served in the war in the British Army. However, about 12,000 Volunteers, led by Eoin MacNeill and dominated by the secret Irish Republican Brotherhood (IRB), refused to join the British war effort and kept the name "Irish Volunteers". Whereas MacNeill intended to use force only to resist the imposition of conscription on Ireland, or to prevent the use of force to disarm of the Volunteers, the IRB men intended to launch an armed rebellion in pursuit of Irish independence.

A smaller organisation, the Irish Citizen Army—originally a workers' defence association under socialist James Connolly—independently planned their own rebellion. The IRB co-opted Connolly onto their supreme council in 1915.

Easter Rising
Weapons for the planned rising were supplied by Germany under the auspices of a leading human rights campaigner, Sir Roger Casement; the shipment included over 20,000 rifles, as well as 10 machine guns. However, the plot was discovered on 21 April 1916 and the weapons were lost when the ship carrying them, the Aud, was scuttled to prevent the arms from falling into the hands of the British.

The IRB had planned the Rising against British rule to break out on 23 April 1916. However, the Volunteers' leader, Eoin MacNeill, found out about the plot at the last minute, and issued countermanding orders to Volunteer units around the country. Nevertheless, the plotters decided to go ahead with their plans on the following day, but as a result less than 2,000 of the 12,000 Volunteers turned out.

The IRB plan was to seize a compact area of central Dublin and launch simultaneous risings around the country. In the event, the rising consisted of a week's street fighting in the Irish capital after which the rebels surrendered. The British used overwhelming force, including over 16,000 troops, artillery, and a naval gunboat, to put down the rebellion. Over half the 500 or so killed were civilians caught in the crossfire. It was during the Rising that the Volunteers began to refer to themselves as the Irish Republican Army.

The leaders seized the General Post Office (GPO), raising two flags: a green flag bearing the legend "Irish Republic" and the Tricolour, and proclaiming independence for Ireland. The Rising later became a celebrated episode for Irish nationalists. The rebel Volunteers were a minority faction among Irish nationalists and up to 200,000 Irishmen were serving on the British side in the First World War. There were calls for the execution of the "ringleaders" in the major Irish nationalist daily newspaper, the Irish Independent, and local authorities also sought the ringleaders. After the Rising, some Dubliners spat, threw stones at them, and emptied chamber pots down on the rebels as they were marched towards the transport ships that would take them to the Welsh internment camps, while others looked on with sympathy.

However, opinion dramatically shifted to the rebels' side in the next two years. Initially, this was caused by the revulsion over the summary executions of 16 leaders—some of whom, such as James Connolly, who was too weak to stand from wounds sustained in the fighting—and of other people thought complicit in the rebellion. As one observer described, "the drawn-out process of executing the leaders of the rising, it was like watching blood seep from behind a closed door." Opinion shifted even more in favour of the Republicans in 1917–18 with the Conscription Crisis, an attempt by Britain to impose conscription on Ireland to bolster its flagging war effort. By 1917, this was extremely unpopular in Ireland due to heavy casualties on the Western Front.

A small Irish nationalist party, Sinn Féin, was widely, but wrongly, credited with orchestrating the Easter Rising even though its leader Arthur Griffith advocated only Irish self-government under a dual monarchy. The republican survivors of the Rising, under Éamon de Valera, infiltrated and took over Sinn Féin in 1917 and committed the party to founding an independent republic.

From 1916 to 1918, the two dominant nationalist movements, Sinn Féin and the Irish Parliamentary Party, fought a tough series of battles in by-elections. Neither won a decisive victory; however, the Conscription Crisis tipped the balance in favour of Sinn Féin. The party went on to win a clear majority of seats in the 1918 general election: of the 73 seats in which Sinn Féin were elected, 25 were uncontested. The Sinn Féin MPs withdrew from the British Parliament and declared an Irish Republic, with themselves as the legitimate government. They met in their own parliament, which they called the Dáil.

In this new position of strength, the Irish Volunteers, who had been swollen to over 100,000 men in the conscription crisis, were re-organised as the army of this Republic. Hence they began to refer to themselves as the Irish Republican Army.

Emergence of the IRA after the Easter Rising
The first steps towards reorganising the defeated Irish Volunteers were taken on 27 October 1917 when a convention took place in Dublin. This convention, that subsequently became known as an IRA convention, was called to coincide with the Sinn Féin party conference. Nearly 250 people attended the convention; internment prevented many more from attending. In fact, the Royal Irish Constabulary estimated that 162 companies of volunteers were active in the country, although other sources suggest a higher figure of 390.

The proceedings were presided over by Éamon de Valera, who had been elected President of Sinn Féin the previous day. Also on the platform were Cathal Brugha and many others who were prominent in the reorganising of the Volunteers in the previous few months, many of them ex-prisoners.

De Valera was elected president. A national executive was also elected, composed of provincial representatives (including Dublin). In addition, a number of directors were elected to head the various IRA departments. Those elected were: Michael Collins (Director for Organisation); Diarmuid Lynch (Director for Communications); Michael Staines (Director for Supply); Rory O'Connor (Director of Engineering). Seán McGarry was voted General Secretary, while Cathal Brugha was made Chairman of the Resident Executive, which in effect made him Chief of Staff.

The other elected members were: M. W. O'Reilly (Dublin); Austin Stack (Kerry); Con Collins (Limerick); Seán MacEntee (Belfast); Joe O'Doherty (Donegal); Paul Galligan (Cavan); Eoin O'Duffy (Monaghan); Séamus Doyle (Wexford); Peadar Bracken (Offaly); Larry Lardner (Galway); Dick Walsh (Mayo) and another member from Connacht. There were six co-options to make-up the full number when the directors were named from within their ranks. The six were all Dublin men: Eamonn Duggan; Gearóid O'Sullivan; Fintan Murphy; Diarmuid O'Hegarty; Dick McKee and Paddy Ryan.

Of the 26 elected, six were also members of the Sinn Féin National Executive, with Éamon de Valera president of both. Eleven of the 26 were elected Teachta Dála (members of the Dáil) in the 1918 general election and 13 in the May 1921 election.

Dáil Éireann and the IRA
Sinn Féin MPs elected in 1918 fulfilled their election promise not to take their seats in Westminster but instead set up an independent "Assembly of Ireland", or Dáil Éireann, in the Irish language. On 21 January 1919, this new, unofficial parliament assembled in the Mansion House in Dublin. As its first acts, the Dáil elected a prime minister (Príomh Aire), Cathal Brugha, and inaugurated a ministry called the Aireacht. In theory, the IRA was responsible to the Dáil and was the army of the Irish Republic. In practice, the Dáil had great difficulty controlling the actions of the Volunteers.

The new leadership of the Irish Republic worried that the IRA would not accept its authority, given that the Volunteers, under their own constitution, were bound to obey their own executive and no other body. The fear was increased when, on the very day the new national parliament was meeting, 21 January 1919, members of the IRA Third Tipperary Brigade led by Seán Treacy and Dan Breen seized a quantity of gelignite and two Royal Irish Constabulary constables (James McDonnell and Patrick O'Connell) were shot dead in the process.

Technically, the men involved were considered to be in a serious breach of IRA discipline and were liable to be court-martialed, but it was considered more politically expedient to hold them up as examples of a rejuvenated militarism. The conflict soon escalated into guerrilla warfare by what were then known as the Flying Columns in remote areas. Attacks on remote Royal Irish Constabulary (RIC) barracks continued throughout 1919 and 1920, forcing the police to consolidate defensively in the larger towns, effectively placing large areas of the countryside in the hands of the Republicans.

Moves to make the IRA the army of the Dáil and not its rival had begun before the January attack, and were stepped up. On 31 January 1919 the IRA organ, An tÓglách ("The Volunteer") published a list of principles agreed between two representatives of the Aireacht, acting Príomh Aire Cathal Brugha and Richard Mulcahy and the Executive. It made first mention of the organisation treating "the armed forces of the enemy – whether soldiers or policemen – exactly as a national army would treat the members of an invading army".

In the statement the new relationship between the Aireacht and the IRA was defined clearly.
 * The Government was defined as possessing the same power and authority as a normal government.
 * It, and not the IRA, sanctions the IRA campaign;
 * It explicitly spoke of a state of war.

As part of the ongoing strategy to take control of the IRA, Brugha proposed to Dáil Éireann on 20 August 1919 that the Volunteers were to be asked, at this next convention, to swear allegiance to the Dáil. He further proposed that members of the Dáil themselves should swear the same oath. On 25 August Collins wrote to the Príomh Aire, Éamon de Valera, to inform him "the Volunteer affair is now fixed".

Though this was "fixed" at one level, another year passed before the Volunteers took an oath of allegiance to the Irish Republic and its government, "throughout August 1920".

A power struggle continued between Brugha and Collins, both cabinet ministers, over who had the greater influence. Brugha was nominally the superior as Minister for Defence, but Collins's powerbase came from his position as Director of Organisation of the IRA and from his membership on the Supreme Council of the IRB. De Valera resented Collins's clear power and influence, which he saw as coming more from the secretive IRB than from his position as a Teachta Dála (TD) and minister in the Aireacht. Brugha and de Valera both urged the IRA to undertake larger, more conventional military actions for the propaganda effect, but were ignored by Collins and Mulcahy. Brugha at one stage proposed the assassination of the entire British cabinet. This was also discounted due to its presumed negative effect on British public opinion. Moreover, many members of the Dáil, notably Arthur Griffith did not approve of IRA violence and would have preferred a campaign of passive resistance to British rule. The Dáil belatedly accepted responsibility for IRA actions in April 1921, just three months before the end of the Irish War of Independence.

In practice, the IRA was commanded by Collins, with Richard Mulcahy as second in command. These men were able to issue orders and directives to IRA guerrilla units around the country and at times to send arms and organisers to specific areas. However, because of the localised and irregular character of the war, they were only able to exert limited control over local IRA commanders such as Tom Barry, Liam Lynch in Cork and Seán Mac Eoin in Longford.

IRA campaign and organisation
The IRA fought a guerrilla war against the Crown forces in Ireland from 1919 to July 1921. The most intense period of the war was from November 1920 to July 1921. The IRA campaign can broadly be split into three phases. The first, in 1919, involved the re-organisation of the Irish Volunteers as a guerrilla army. Organisers such as Ernie O'Malley were sent around the country to set up viable guerrilla units. On paper, there were 100,000 or so Volunteers enrolled after the conscription crisis of 1918. However, only about 15,000 of these participated in the guerrilla war. In 1919, Collins, the IRA's Director of Intelligence, organised the "Squad"—an assassination unit based in Dublin which killed police involved in intelligence work; the Irish playwright Brendan Behan's father Stephen Behan was a member of this squad. Typical of Collins's sardonic sense of humour, the squad was often referred to as his "Twelve Apostles". In addition, there were some arms raids on Royal Irish Constabulary barracks. By the end of 1919, four Dublin Metropolitan Police and 11 RIC men had been killed. The RIC abandoned most of their smaller rural barracks in late 1919. Around 400 of these were burned in a co-ordinated IRA operation around the country in April 1920.

The second phase of the IRA campaign, roughly from January to July 1920, involved attacks on the fortified police barracks located in the towns. Between January and June 1920, 16 of these were destroyed and 29 badly damaged. Several events of late 1920 greatly escalated the conflict. Firstly, the British declared martial law in parts of the country—allowing for internment and executions of IRA men. Secondly they deployed paramilitary forces, the Black and Tans and Auxiliary Division, and more British Army personnel into the country. Thus, the third phase of the war (roughly August 1920–July 1921) involved the IRA taking on a greatly expanded British force, moving away from attacking well defended barracks and instead using ambush tactics. To this end the IRA was re-organised into "flying columns"—permanent guerrilla units, usually about 20 strong, though sometimes larger. In rural areas, the flying columns usually had bases in remote mountainous areas.

While most areas of the country saw some violence in 1919–1921, the brunt of the war was fought in Dublin and the southern province of Munster. In Munster, the IRA carried out a significant number of successful actions against British troops, for instance the ambushing and killing of 17 of 18 Auxiliaries by Tom Barry's column at Kilmicheal in West Cork in November 1920, or Liam Lynch's men killing 13 British soldiers near Millstreet early in the next year. At the Crossbarry Ambush in March 1921, 100 or so of Barry's men fought a sizeable engagement with a British column of 1,200, escaping from the British encircling manoeuvre. In Dublin, the "Squad" and elements of the IRA Dublin Brigade were amalgamated into the "Active Service Unit", under Oscar Traynor, which tried to carry out at least three attacks on British troops a day. Usually, these consisted of shooting or grenade attacks on British patrols. Outside Dublin and Munster, there were only isolated areas of intense activity. For instance, the County Longford IRA under Seán Mac Eoin carried out a number of well planned ambushes and successfully defended the village of Ballinalee against Black and Tan reprisals in a three-hour gun battle. In County Mayo, large scale guerrilla action did not break out until spring 1921, when two British forces were ambushed at Carrowkennedy and Tourmakeady. Elsewhere, fighting was more sporadic and less intense.

In Belfast, the war had a character all of its own. The area had a Protestant and Unionist majority and IRA actions were responded to with reprisals against the Catholic population, including killings (such as the McMahon Murders) and the burning of many homes – as on Belfast's Bloody Sunday. The IRA in Belfast and the north generally, although involved in protecting the Catholic community from loyalists and state forces, undertook an arson campaign against factories and commercial premises. The violence in Belfast alone, which continued until October 1922 long after the truce in the rest of the country, claimed the lives of between 400 and 500 people.

In April 1921, the IRA was again reorganised, in line with the Dáil's endorsement of its actions, along the lines of a regular army. Divisions were created based on region, with commanders being given responsibility, in theory, for large geographical areas. In practice, this had little effect on the localised nature of the guerrilla warfare.

In May 1921, the IRA in Dublin attacked and burned the The Custom House. The action was a serious setback as five members were killed and eighty captured.

By the end of the war, in July 1921, the IRA was very hard pressed by the deployment of more British troops into the most active areas and a chronic shortage of arms and ammunition. It has been estimated that the IRA had only about 3,000 rifles (mostly captured from the British) during the war, with a larger number of shotguns and pistols. An ambitious plan to buy arms from Italy in 1921 collapsed when the money did not reach the arms dealers. Towards the end of the war, some Thompson submachine guns were imported from the United States; however 450 of these were intercepted by the American authorities and the remainder only reached Ireland shortly before the Truce.

By June 1921, Collins' assessment was that the IRA was within weeks, possibly even days, of collapse. It had few weapons or ammunition left. Moreover, almost 5,000 IRA men had been imprisoned or interned and over 500 killed. Collins and Mulcahy estimated that the number of effective guerrilla fighters was down to 2,000–3,000. However in the summer of 1921, the war was abruptly ended.

Violent exchange
The Irish War of Independence was a brutal and bloody affair, with violence and acts of extreme brutality on both sides. The British sent hundreds of World War I veterans to assist the RIC. The veterans at first wore a combination of black police uniforms and tan army uniforms (because of shortages), which, according to one etymology, inspired the nickname Black and Tans. The brutality of the "Black and Tans" is now legendary, although the most excessive repression attributed to the Crown's forces was often that of the Auxiliary Division of the Constabulary. One of the strongest critics of the Black and Tans was King George V who in May 1921 told Lady Margery Greenwood that ‘he hated the idea of the ‘Black and Tans”.’

The most high profile atrocity of the war took place in Dublin in November 1920, and is still known as Bloody Sunday. In the early hours of the morning, Collins' "Squad" killed fourteen people of whom nine were British agents, some in front of their wives. In reprisal, that afternoon, British forces opened fire on a football crowd at Croke Park, killing 14 civilians. Towards the end of the day, two prominent Republicans and a friend of theirs were arrested and killed by Crown Forces.

The IRA was also involved in the destruction of many stately homes in Munster. These belonged to prominent Loyalists who were aiding the Crown forces, and were burnt to discourage the British policy of destroying the homes of Republicans, suspected and actual. The Church of Ireland Gazette recorded numerous instances of Unionists and Loyalists being shot, burnt or forced from their homes during the early 1920s. In County Cork between 1920 and 1923 the IRA shot over 200 civilians of whom over 70 (or 36%) were Protestants: five times the percentage of Protestants in the civilian population. This was due to the historical inclination of Protestants towards loyalty to the United Kingdom. A convention of Irish Protestant Churches in Dublin in May 1922 signed a resolution placing "on record" that "hostility to Protestants by reason of their religion has been almost, if not wholly, unknown in the twenty-six counties in which Protestants are in the minority."

Many historic buildings in Ireland were destroyed during the war, most famously the Custom House in Dublin, which was disastrously attacked on de Valera's insistence, to the horror of the more militarily experienced Collins. As he feared, the destruction proved a pyrrhic victory for the Republic, with so many IRA men killed or captured that the IRA in Dublin suffered a severe blow.

This was also a period of social upheaval in Ireland, with frequent strikes as well as other manifestations of class conflict. In this regard, the IRA acted to a large degree as an agent of social control and stability, driven by the need to preserve cross-class unity in the national struggle, and on occasion being used to break strikes.

Assessments of the effectiveness of the IRA's campaign vary. They were never in a position to engage in conventional warfare. IRA Chief-of-Staff Richard Mulcahy bemoaned the fact that they had not been able to drive the British "out of anything bigger than a fairly good size police barracks". On the other hand, the guerrilla warfare of 1919–21 had made Ireland ungovernable except by military means. The political, military and financial costs of remaining in Ireland were higher than the British government was prepared to pay and this in a sense forced them into negotiations with the Irish political leaders. According to historian Michael Hopkinson, the guerrilla warfare "was often courageous and effective". Historian David Fitzpatrick observes, "The guerrilla fighters...were vastly outnumbered by the forces of the Crown... The success of the Irish Volunteers in surviving so long is therefore noteworthy."

Truce and Treaty
David Lloyd George, the British Prime Minister, at the time, found himself under increasing pressure (both internationally and from within the British Isles) to try to salvage something from the situation. This was a complete reversal on his earlier position. He had consistently referred to the IRA as a "murder gang" up until then. An unexpected olive branch came from King George V, who, in a speech in Belfast called for reconciliation on all sides, changed the mood and enabled the British and Irish Republican governments to agree to a truce. The Truce was agreed on 11 July 1921. On 8 July, de Valera met General Macready, the British commander in chief in Ireland and agreed terms. The IRA was to retain its arms and the British Army was to remain in barracks for the duration of peace negotiations. Many IRA officers interpreted the truce only as a temporary break in fighting. They continued to recruit and train volunteers, with the result that the IRA had increased its number to over 72,000 men by early 1922. Negotiations on an Anglo-Irish Treaty took place in late 1921 in London. The Irish delegation was led by Arthur Griffith and Michael Collins.

The most contentious areas of the Treaty for the IRA were abolition of the Irish Republic declared in 1919, the status of the Irish Free State as a dominion in the British Commonwealth and the British retention of the so-called Treaty Ports on Ireland's south coast. These issues were the cause of a split in the IRA and ultimately, the Irish Civil War.

Under the Government of Ireland Act 1920, Ireland was partitioned, creating Northern Ireland and Southern Ireland. Under the terms of the Anglo-Irish agreement of 6 December 1921, which ended the war (1919–1921), Northern Ireland was given the option of withdrawing from the new state, the Irish Free State, and remaining part of the United Kingdom. The Northern Ireland parliament chose to do that. An Irish Boundary Commission was then set up to review the border.

Irish leaders expected that it would so reduce Northern Ireland's size, by transferring nationalist areas to the Irish Free State, as to make it economically unviable. Partition was not by itself the key breaking point between pro- and anti-Treaty campaigners; both sides expected the Boundary Commission to greatly reduce Northern Ireland. Moreover, Michael Collins was planning a clandestine guerrilla campaign against the Northern state using the IRA. In early 1922, he sent IRA units to the border areas and sent arms to northern units. It was only afterwards, when partition was confirmed, that a united Ireland became the preserve of anti-Treaty Republicans.

The IRA and the Treaty
The IRA leadership was deeply divided over the decision by the Dáil to ratify the Treaty. Despite the fact that Michael Collins – the de facto leader of the IRA – had negotiated the Treaty, many IRA officers were against it. Of the General Headquarters (GHQ) staff, nine members were in favour of the Treaty while four opposed it. Many of the IRA rank-and-file were against the Treaty and in January–June 1922, their discontent developed into open defiance of the elected civilian Provisional government of Ireland. Anti-treaty writer Dorothy Macardle has claimed that 70 to 80 percent of the IRA was against the Treaty.

Both sides agreed that the IRA's allegiance was to the (elected) Dáil of the Irish Republic, but the anti-Treaty side argued that the decision of the Dáil to accept the Treaty (and set aside the Irish Republic) meant that the IRA no longer owed that body its allegiance. They called for the IRA to withdraw from the authority of the Dáil and to entrust the IRA Executive with control over the army. On 16 January, the first IRA division – the 2nd Southern Division led by Ernie O'Malley – repudiated the authority of the GHQ. A month later, on 18 February, Liam Forde, O/C of the IRA Mid-Limerick Brigade, issued a proclamation stating that: "We no longer recognise the authority of the present head of the army, and renew our allegiance to the existing Irish Republic". This was the first unit of the IRA to break with the pro-Treaty government.

On 22 March, Rory O'Connor held what was to become an infamous press conference and declared that the IRA would no longer obey the Dáil as (he said) it had violated its Oath to uphold the Irish Republic. He went on to say that "we repudiate the Dáil … We will set up an Executive which will issue orders to the IRA all over the country." In reply to the question on whether this meant they intended to create a military dictatorship, O’Connor said: "You can take it that way if you like."

On 28 March, the (anti-Treaty) IRA Executive issued statement stating that Minister of Defence (Richard Mulcahy) and the Chief-of-Staff (Eoin O'Duffy) no longer exercised any control over the IRA. In addition, it ordered an end to the recruitment to the new military and police forces of the Provisional Government. Furthermore, it instructed all IRA units to reaffirm their allegiance to the Irish Republic on 2 April.

The stage was set for civil war over the Treaty.

Civil War
The pro-treaty IRA soon became the nucleus of the new (regular) Irish National Army created by Collins and Richard Mulcahy. British pressure, and tensions between the pro- and anti-Treaty factions of the IRA, led to a bloody civil war, ending in the defeat of the anti-Treaty faction. On 24 May 1923, Frank Aiken, the (anti-treaty) IRA Chief-of-Staff, called a cease-fire. Many left political activity altogether, but a minority continued to insist that the new Irish Free State, created by the "illegitimate" Treaty, was an illegitimate state. They asserted that their "IRA Army Executive" was the real government of a still-existing Irish Republic. The IRA of the Civil War and subsequent organisations that have used the name claim lineage from that group, which is covered in full at Irish Republican Army (1922–1969).

''For information on later organisations using the name Irish Republican Army, see the table below. For a genealogy of organisations using the name IRA after 1922, see List of organisations known as the Irish Republican Army''.