This is a timeline of the Irish Civil War, which took place between June 1922 and May 1923. It followed the Irish War of Independence (1919–1921), and accompanied the establishment of the Irish Free State as an entity independent from the United Kingdom of Great Britain and Ireland.
The conflict was waged between two opposing groups of Irish nationalists: the forces of the new Irish Free State, who supported the Anglo-Irish Treaty under which the state was established, and the republican opposition, for whom the Treaty represented a betrayal of the Irish Republic.
The government of the Irish Free State (established as a provisional government in January 1922 and as a full government in December 1922) was ultimately victorious. The anti-Treaty forces called a ceasefire in April 1923 and ordered their men to "dump arms" in May 1923.
The war involved both conventional warfare (late June–August 1922) when the Free State forces took the major towns and cities, and then a longer period of guerrilla warfare (September 1922 – April 1923) as the anti-Treaty forces were gradually brought to a standstill.
Build up
January 1922 7 January – The Anglo-Irish Treaty is passed in the Dáil (Parliament of the Irish Republic) by 64 votes to 57. 14 January – A Provisional Government is set up to administer the handover from British rule to the new Irish Free State. The Cabinet is almost the same as that of the Irish Republic, with the exception of Éamon de Valera, Cathal Brugha and Austin Stack, who resign over the acceptance of the Treaty.
February 1922 18 February – An Anti-Treaty IRA unit under Ernie O'Malley seizes an RIC barracks in Clonmel, taking 40 policemen prisoner and capturing 600 rifles and thousands of rounds of ammunition. Anti-Treaty IRA leader Séumas Robinson closes down The Nationalist newspaper (Clonmel) over its support for the Treaty. Rory O'Connor has the Freeman's Journal closed down for the same reason.
March 1922 A stand-off occurs in Limerick between 700 pro-treaty IRA men under Michael Brennan and 800 Anti-Treaty IRA fighters under Ernie O'Malley over who will take over the military barracks, which were being abandoned by British troops. After negotiations between the mayor of Limerick, Stephen M. O'Mara, Anti-Treaty leader Liam Lynch and Pro-Treaty leader Richard Mulcahy, fighting is averted. On 12 March, it is decided that troops from outside Limerick will return to their own areas and that Limerick IRA men would divide the two military garrisons there between pro- and Anti-Treaty units. Limerick Corporation will oversee the maintenance of the RIC barracks. More confrontations result over the occupation of former British garrisons at Birr, Renmore and Templemore. 17 March - IRA leaders meet in Dublin and set up a temporary council with Liam Lynch as chief of staff. 26 March – 200 IRA delegates meet in an "Army Convention" and vote to repudiate the Treaty. They also reject the authority of the Dáil to accept the Treaty and set up their own 16-man "Army Executive". See also IRA and the Anglo-Irish Treaty 29 March – Anti-Treaty IRA units in Cork under Sean Hegarty raid the British tug Upnor at sea. They take between 400 and 1,500 rifles, 60 machine guns, 700 handguns and over 25,000 rounds of ammunition, which they then distribute to Anti-Treaty IRA units. The Provisional Government's newly formed National Army takes over the British barracks at Beggar's Bush in Dublin.
April 1922 1 April – Belfast Police Constable George Turner shot and killed; in retaliation five men shot and killed and six children wounded of whom one died of wounds in Sinn Féin area of Belfast. 10 April – Lieutenant Michael Sweeney, aged 21 years, 4th Battalion, Dublin Brigade of the Anti-Treaty IRA was killed by Free State troops at the junction of Grafton St and Nassau Street, Dublin while being transported under armed guard in a military lorry. Sweeney, who had previously been injured in his left leg by a landmine explosion stood up to hang onto the overhead bars in order to stretch the aforementioned leg. One of the escorts stepped forward and shot him in the back of the neck. Sweeney was taken to Jervis St Hospital where he died ten minutes after arrival. The seventeen year old soldier who shot him later testified that was trying to escape. An inquest ruled that death was accidental. 14 April – Rory O'Connor, Mellows and others lead 200 Anti-Treatyites in taking over the Four Courts and several other public buildings around Dublin in a show of defiance calculated to provoke a response by the British troops still stationed in Dublin. 20 April – There is 'intense firing' for two hours, starting at midnight, by Anti-Treaty fighters on the Pro-Treaty troops in Dublin stationed at the Provisional Government headquarters in Merrion Square, the Bank of Ireland on College Green, the telephone exchange and City Hall, Dublin. Three people are wounded. The Four Courts Anti-Treaty garrison denies knowledge of the attack. 25 April – A National Army brigadier-general, George Adamson, is shot dead in suspicious circumstances in Athlone. 27 April – The week after an abortive attempt by the anti-Treaty IRA to occupy the military barracks in Mullingar, two men – National Army adjutant Patrick Columb and anti-Treaty republican Joe Leavy – die in clashes in the town. 30 April – In Westport, County Mayo, four Pro-Treaty troops are arrested by Anti-Treaty Irregulars. They are taken to Castlebar and charged by a Republican Court of illegal recruitment. The men refuse to recognize the court. The men are threatened with execution if they continue to recruit for the Pro-Treaty forces.
May 1922 2 May – Around 300 Irregulars take over the centre of Kilkenny, including the city hall, the Protestant cathedral and Kilkenny Castle. The Irregulars order the closure of the Ulster bank branch. The Provisional government hold the Military Barracks, the Jail and the Bank of Ireland. The Provision government sends 200 troops by train from Dublin to dislodge them. Fighting breaks out when the troops from Dublin arrive and there are up to 18 casualties. A truce is then brokered whereby both sides garrison different posts in the town. 3 May – Pro- and Anti-Treaty leaders announce a "truce" in the Dáil to try to prevent civil war. 4 May – Pro- and Anti-Treaty IRA forces clash in County Donegal. There is firefight at Buncrana. Around 16 Irregulars enter the town in order to rob the Hibernian Bank. Free state regulars learn about the attack and confront the raiders. Two Irregulars are killed and two are wounded. There are five civilians hit in the crossfire. One of which was a nine-year-old girl who later died in hospital. A nineteen-year-old woman also died later in hospital. Reports of the fighting are relayed to Ballybofey, which is the local headquarters of the Free State forces. When reinforcements travel through Newtowncunningham, they are ambushed. Three Free Staters are killed and three are seriously wounded. 5 May – Irregulars raid the Bank of Ireland branch in Westport and take £2,673. They leave a document indicating that the Provisional Government had refused to finance them and that they were taking the money to cover expenses. There are similar robberies in Waterford, Clonmel, Ballinrobe, Claremorris, Ballina and Sligo. In total, around £100,000 is seized from the Bank of Ireland. At Newtowncunningham, County Donegal, a Free State motor convoy is ambushed by Republicans, one Pro-treaty soldier is killed outright and four fatally wounded.Derry Journal, 5 May 1922 20 May – Michael Collins and Éamon de Valera sign a Pact, in which the pro- and Anti-Treaty wings of Sinn Féin would jointly contest the upcoming first election of the new state. There is a firefight at Gormanston railway station, County Meath, between RIC men and Anti-Treaty fighters. One Anti-Treaty officer and one RIC man are killed.
June 1922
14 June - Michael Collins urges voters to vote "for the candidates they think best of" in Cork.Michael Collins, a Biography, Tim Pat Coogan p. 329. 16 June – A Free State soldier, William Murphy, is killed. 16 June – 1922 Irish general election – The Pro-Treaty Sinn Féin party wins the election, despite the Collins/De Valera Pact stating the election was not to be held on the issue of the Treaty but to form a Coalition Government, with 239,193 votes to 133,864 for Anti-Treaty Sinn Féin. A further 247,226 people voted for other parties, all of whom supported the Treaty (except Unionist Party) 18 June – At the Third Army Convention, a proposal by Tom Barry for war to be restarted with the British is narrowly defeated in the face of opposition by Liam Lynch. A hardline faction walks out and establishes a new GHQ command in the Four Courts. Joe McKelvey becomes IRA chief of staff. 22 June – Assassination in London of Henry Hughes Wilson by IRA men in retaliation for attacks on Catholics in Northern Ireland. Research will eventually come to suggest that it was Pro-Treaty leader Michael Collins who ordered the killing, but at the time, Winston Churchill assumes that the Anti-Treaty Four Courts garrison is responsible and warns Collins that if he does not act, British troops will be used to re-take Dublin. The assassins are hanged by the British on 10 August. 26 June – The Four Courts garrison kidnaps Free State General JJ "Ginger" O'Connell in retaliation for the arrest of Leo Henderson I/C Belfast Boycott. 27 June – Collins gives a final ultimatum to the Four Courts garrison to surrender before they are attacked. 28 June – Michael Collins borrows two British 18-pounder field guns to bombard the Four Courts at 4.15 am, marking the definitive start of the Civil War. Passenger trains to Galway, Westport, Ballina and Sligo are suspended. A number of buildings in Ballina, including the post office, are seized by Irregulars.
Hostilities 28 June–5 July – Battle of Dublin Fighting breaks out in Drogheda between pro- and Anti-Treaty units. One man on either side and a woman civilian are killed in a gun battle in the town. Many other civilians including the town's mayor are wounded. The Republicans are left in control of the town. The Anti-Treaty fighters blow up the railway bridge to the south of Drogheda, isolating it from Dublin. An Anti-Treaty fighter is killed in fighting Tipperary town. 29 June – British give Collins two more 18-pounders to increase the bombardment of the Four Courts. Free State troops storm the eastern buildings of the complex, losing 3 dead and 14 wounded. Oscar Traynor leads Anti-Treaty members of the IRA's 1st Dublin Brigade to occupy O'Connell Street in order to help the Four Courts garrison. His men also take up positions in York Street, South Circular Road, Capel Street, Parnell Square and Dolphin's Barn. Skirmish in Listowel, County Kerry, Free State troops surrender their arms to Republicans. Free State troops surround republican fighters at Finner Camp, County Donegal. After a two-hour gun battle, two anti-Treatyites are killed and 50 surrender. Elsewhere in the county, another 200 republicans are taken prisoner. 30 June – Anti-Treaty commander in the Four Courts, Paddy O'Brien is wounded by shrapnel. Ernie O'Malley assumes command. In the morning there is a truce to remove the wounded. Shortly afterwards, a massive explosion destroys the western wing of the Four Courts and the Irish Public Records Office along with it. It is thought to have been caused when fires from the artillery bombardment set off munitions stored there, although Free State troops claim that the building was mined. 20 Free State soldiers are maimed in the blast. O'Malley surrenders the Four Courts when Oscar Traynor sends word that he cannot break through to help them. Members of the IRA Army Executive Liam Mellows, Rory O'Connor, Joe McKelvey and Dick Barret are among the prisoners, but O'Malley himself escapes.