This ended British rule in most of Ireland and, after a ten-month transitional period overseen by the Provisional Government, the Irish Free State was created as a self-governing Dominion on 6 December 1922.

In the course of the war, about a quarter of Ireland was put under martial law, mostly in Munster; in the rest of the country British authority was not deemed sufficiently threatened to warrant it.

Although some republican leaders, notably Éamon de Valera, favoured classic conventional warfare to legitimise the new republic in the eyes of the world, the more practically experienced Collins and the broader IRA leadership opposed these tactics as they had led to the military débacle of 1916.

[57] Similarly, in May 1920, Dublin dockers refused to handle any war matériel and were soon joined by the Irish Transport and General Workers' Union, who banned railway drivers from carrying members of the British forces.

[67] In March 1920, Tomás Mac Curtain, the Sinn Féin Lord Mayor of Cork, was shot dead in front of his wife at his home, by men with blackened faces who were seen returning to the local police barracks.

The jury at the inquest into his death returned a verdict of wilful murder against David Lloyd George (the British Prime Minister) and District Inspector Swanzy, among others.

One spy who escaped with his life was F. Digby Hardy, who was exposed by Arthur Griffith before an "IRA" meeting, which in fact consisted of Irish and foreign journalists, and then advised to take the next boat out of Dublin.

[72] In response to and retaliation for IRA actions, in the summer of 1920, the Tans burned and sacked numerous small towns throughout Ireland, including Balbriggan,[73] Trim,[74] Templemore[75] and others.

In the early morning, Collins' Squad attempted to wipe out leading British intelligence operatives in the capital, in particular the Cairo Gang, killing 16 men (including two cadets, one alleged informer, and one possible case of mistaken identity) and wounding five others.

Most of the actions in the war were on a smaller scale than this, but the IRA did have other significant victories in ambushes, for example at Millstreet in Cork and at Scramogue in Roscommon, also in March 1921 and at Tourmakeady and Carrowkennedy in Mayo in May and June.

Equally common, however, were failed ambushes, the worst of which, for example at Mourneabbey,[96] Upton and Clonmult in Cork in February 1921, saw six, three, and twelve IRA men killed respectively and more captured.

Talks that had looked promising the previous year had petered out in December when Prime Minister of the United Kingdom David Lloyd George insisted that the IRA first surrender their arms.

Fresh talks, after the Prime Minister had come under pressure from H. H. Asquith and the Liberal opposition, the Labour Party and the Trades Union Congress, resumed in the spring and resulted in the truce.

It called on "all Irishmen to pause, to stretch out the hand of forbearance and conciliation, to forgive and to forget, and to join in making for the land they love a new era of peace, contentment, and good will".

[103] Seizing the momentum, Lloyd George wrote to Éamon de Valera as "the chosen leader of the great majority in Southern Ireland" on 24 June, suggesting a conference.

[105] On 18 February 1922, Ernie O'Malley's IRA unit raided the RIC barracks at Clonmel, taking 40 policemen prisoner and seizing over 600 weapons and thousands of rounds of ammunition.

[citation needed] Ultimately, the peace talks led to the negotiation of the Anglo-Irish Treaty (6 December 1921), which was then ratified in triplicate: by Dáil Éireann on 7 January 1922 (so giving it legal legitimacy under the governmental system of the Irish Republic), by the House of Commons of Southern Ireland in January 1922 (so giving it constitutional legitimacy according to British theory of who was the legal government in Ireland), and by both Houses of the British parliament.

A majority[citation needed] of the pre-Truce IRA who had fought in the War of Independence, led by Liam Lynch, refused to accept the Treaty and in March 1922 repudiated the authority of the Dáil and the new Free State government, which it accused of betraying the ideal of the Irish Republic.

A hardline group of anti-Treaty IRA men occupied several public buildings in Dublin in an effort to bring down the Treaty and restart the war with the British.

[109] Desperate to get the new Irish Free State off the ground and under British pressure, Collins attacked the anti-Treaty militants in Dublin, causing fighting to break out around the country.

He warned, "Loyalist leaders now feel the situation is so desperate that unless the Government will take immediate action, it may be advisable for them to see what steps can be taken towards a system of organised reprisals against the rebels".

In February, as reprisal for the shooting of a Special Constable, USC and UVF men burned ten Catholic homes and a priest's house in Rosslea, County Fermanagh.

[145] Despite the Dáil's acceptance of the Anglo-Irish Treaty in January 1922, which confirmed the future existence of Northern Ireland, there were clashes between the IRA and British forces along the new border from early 1922.

The USC unit was travelling by train from Belfast to Enniskillen (both in Northern Ireland), but the Provisional Government was unaware that British forces would be crossing through its territory.

[156] Winston Churchill had arranged a meeting between Collins and James Craig on 21 January and the southern boycott of Belfast goods was lifted but then re-imposed after several weeks.

[162] On 17 June, in revenge for the killing of two Catholics by Specials, Frank Aiken's IRA unit shot dead six Protestant civilians in Altnaveigh, south Armagh.

[169] Conditions during internment were not always good—during the 1920s, the vessel HMS Argenta was moored in Belfast Lough and used as a prison ship for the holding of Irish republicans by the British government after Bloody Sunday.

"[175] Thomas Gilmartin, the Archbishop of Tuam, issued a letter saying that IRA men who took part in ambushes "have broken the truce of God, they have incurred the guilt of murder".

The long-planned evacuation from dozens of barracks in what the army called "Southern Ireland" started on 12 January 1922, following the ratification of the Treaty and took nearly a year, organised by General Nevil Macready.

Finally on 17 December 1922 The Royal Barracks (now housing collections of the National Museum of Ireland) was transferred to General Richard Mulcahy and the garrison embarked at Dublin Port that evening.