The Irish War of Independence (Irish: Cogadh na Saoirse)[4] or Anglo-Irish War was a guerrilla war fought in Ireland from 1919 to 1921 between the Irish Republican Army (IRA, the army of the Irish Republic) and British forces: the British Army, along with the quasi-military Royal Irish Constabulary (RIC) and its paramilitary forces the Auxiliaries and Ulster Special Constabulary (USC). It was an escalation of the Irish revolutionary period into warfare.
In April 1916, Irish republicans launched the Easter Rising against British rule and proclaimed an Irish Republic. Although it was crushed after a week of fighting, the rising and the British response led to greater popular support for Irish independence.  In the December 1918 election, the republican party Sinn Féin won a landslide victory in Ireland. On 21 January 1919 they formed a breakaway government (Dáil Éireann) and declared Irish independence. That day, two RIC officers were shot dead in the Soloheadbeg ambush by IRA volunteers acting on their own initiative. The conflict developed gradually. For much of 1919, IRA activity involved capturing weaponry and freeing republican prisoners, while the Dáil set about building a state. In September, the British government outlawed the Dáil and Sinn Féin and the conflict intensified. The IRA began ambushing RIC and British Army patrols, attacking their barracks and forcing isolated barracks to be abandoned. The British government bolstered the RIC with recruits from Britain—the Black and Tans and Auxiliaries—who became notorious for ill-discipline and reprisal attacks on civilians,[5] some of which were authorized by the British government.[6] Thus the conflict is sometimes called the "Black and Tan War".[7][8][9] The conflict also involved civil disobedience, notably the refusal of Irish railwaymen to transport British forces or military supplies.
In mid-1920, republicans won control of most county councils, and British authority collapsed in most of the south and west, forcing the British government to introduce emergency powers. About 300 people had been killed by late 1920, but the conflict escalated in November. On Bloody Sunday in Dublin, 21 November 1920, fourteen British intelligence operatives were assassinated in the morning; then in the afternoon the RIC opened fire on a crowd at a Gaelic football match, killing fourteen civilians and wounding 65. A week later, seventeen Auxiliaries were killed by the IRA in the Kilmichael Ambush in County Cork. The British government declared martial law in much of southern Ireland. The centre of Cork city was burnt out by British forces in December 1920. Violence continued to escalate over the next seven months, when 1,000 people were killed and 4,500 republicans were interned. Much of the fighting took place in Munster (particularly County Cork), Dublin and Belfast, which together saw over 75 percent of the conflict deaths.[10]
The conflict in parts of Ulster had a sectarian aspect. While the Catholic minority there mostly backed Irish independence, the Protestant majority were mostly unionist/loyalist. A Special Constabulary was formed, made up mostly of Protestants, and loyalist paramilitaries were active. They attacked Catholics in reprisal for IRA actions, and in Belfast a sectarian conflict raged in which almost 500 were killed, most of them Catholics.[11]
In May 1921, Ireland was partitioned under British law by the Government of Ireland Act, which created Northern Ireland. Both sides agreed to a ceasefire (or 'truce') on 11 July 1921.  The post-ceasefire talks led to the signing of the Anglo-Irish Treaty on 6 December 1921. This ended British rule in most of Ireland and, after a ten-month transitional period overseen by a provisional government, the Irish Free State was created as a self-governing Dominion on 6 December 1922. Northern Ireland remained within the United Kingdom. After the ceasefire, violence in Belfast and fighting in border areas of Northern Ireland continued, and the IRA launched a failed Northern offensive in May 1922. In June 1922, disagreement among republicans over the Anglo-Irish Treaty led to the ten-month Irish Civil War. The Irish Free State awarded 62,868 medals for service during the War of Independence, of which 15,224 were issued to IRA fighters of the flying columns.[12]
Origins of the conflict
Home Rule Crisis

Since the 1880s, Irish nationalists in the Irish Parliamentary Party (IPP) had been demanding Home Rule, or self-government, from Britain. Fringe organisations, such as Arthur Griffith's Sinn Féin, instead argued for some form of Irish independence, but they were in a small minority.
The demand for Home Rule was eventually granted by the British Government in 1912, immediately prompting a prolonged crisis within the United Kingdom as Ulster unionists formed an armed organisation – the Ulster Volunteers (UVF) – to resist this measure of devolution, at least in territory they could control. In turn, nationalists formed their own paramilitary organisation, the Irish Volunteers.
The British Parliament passed the Third Home Rule Act on 18 September 1914 with an amending Bill for the partition of Ireland introduced by Ulster Unionist MPs, but the Act's implementation was immediately postponed by the Suspensory Act 1914 due to the outbreak of the First World War in the previous month. The majority of nationalists followed their IPP leaders and John Redmond's call to support Britain and the Allied war effort in Irish regiments of the New British Army, the intention being to ensure the commencement of Home Rule after the war. But a significant minority of the Irish Volunteers opposed Ireland's involvement in the war. The Volunteer movement split, a majority leaving to form the National Volunteers under Redmond. The remaining Irish Volunteers, under Eoin MacNeill, held that they would maintain their organisation until Home Rule had been granted. Within this Volunteer movement, another faction, led by the separatist Irish Republican Brotherhood, began to prepare for a revolt against British rule in Ireland.
Easter Rising

The plan for revolt was realised in the Easter Rising of 1916, in which the Volunteers launched an insurrection whose aim was to end British rule. The insurgents issued the Proclamation of the Irish Republic, proclaiming Ireland's independence as a republic. The Rising, in which over four hundred people died, was almost exclusively confined to Dublin and was put down within a week, but the British response, executing the leaders of the insurrection and arresting thousands of nationalist activists, galvanised support for the separatist Sinn Féin– the party which the republicans first adopted and then took over as well as followers from Countess Markievicz, the female lead of the Easter Rising. By now, support for the British war effort was on the wane, and Irish public opinion was shocked and outraged by some of the actions committed by British troops, particularly the murder of Francis Sheehy-Skeffington and the imposition of wartime martial law.
First Dáil

In April 1918, the British Cabinet, in the face of the crisis caused by the German Spring Offensive, attempted with a dual policy to simultaneously link the enactment of conscription into Ireland with the implementation of Home Rule, as outlined in the report of the Irish Convention of 8 April 1918. This further alienated Irish nationalists and produced mass demonstrations during the Conscription Crisis of 1918. In the 1918 general election Irish voters showed their disapproval of British policy by giving Sinn Féin 70% (73 seats out of 105,) of Irish seats, 25 of these uncontested. Sinn Féin won 91% of the seats outside of Ulster on 46.9% of votes cast, but was in a minority in Ulster, where unionists were in a majority. Sinn Féin pledged not to sit in the UK Parliament at Westminster, but rather to set up an Irish Parliament. This parliament, known as the First Dáil, and its ministry, called the Aireacht, consisting only of Sinn Féin members, met at the Mansion House on 21 January 1919. The Dáil reaffirmed the 1916 Proclamation with the Irish Declaration of Independence,[13] and issued a Message to the Free Nations of the World, which stated that there was an "existing state of war, between Ireland and England". The Irish Volunteers were reconstituted as the "Irish Republican Army" or IRA. The IRA was perceived by some members of Dáil Éireann to have a mandate to wage war on the British Dublin Castle administration.
Forces
British

The heart of British power in Ireland was the Dublin Castle administration, often known to the Irish as "the Castle".[14] The head of the Castle administration was the Lord Lieutenant, to whom a Chief Secretary was responsible, leading—in the words of the British historian Peter Cottrell—to an "administration renowned for its incompetence and inefficiency".[14] Ireland was divided into three military districts. During the course of the war, two British divisions, the 5th and the 6th, were based in Ireland with their respective headquarters in the Curragh and Cork.[14] By July 1921 there were 50,000 British troops based in Ireland; by contrast there were 14,000 soldiers in metropolitan Britain.[15] The two main police forces in Ireland were the Royal Irish Constabulary (RIC) and the Dublin Metropolitan Police.[16] Of the 17,000 policemen in Ireland, 513 were killed by the IRA between 1919–21 while 682 were wounded.[16] Of the RIC's senior officers, 60% were Irish Protestants and rest Catholic while 70% of the rank and file of the RIC were Irish Catholic with the rest Protestant.[16] The RIC was trained for police work, not war, and was woefully ill-prepared to take on counter-insurgency duties.[17] Until March 1920, London regarded the unrest in Ireland as primarily an issue for the police and did not regard it as a war.[18] The purpose of the Army was to back up the police. During 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.[15] During the course of the war, the British created two paramilitary police forces to supplement the work of the RIC, recruited mostly from World War I veterans, namely the Temporary Constables (better known as the "Black and Tans") and the Temporary Cadets or Auxiliary Division (known as the "Auxies").[19]
Irish republican
On 25 November 1913, the Irish Volunteers were formed by Eoin MacNeill in response to the paramilitary Ulster Volunteer Force that had been founded earlier in the year to fight against Home Rule.[20] Also in 1913, the Irish Citizen Army was founded by the trade unionists and socialists James Larkin and James Connolly following a series of violent incidents between trade unionists and the Dublin police in the Dublin lock-out.[21] In June 1914, Nationalist leader John Redmond forced the Volunteers to give his nominees a majority on the ruling committee. When, in September 1914, Redmond encouraged the Volunteers to enlist in the British Army, a faction led by Eoin MacNeill broke with the Redmondites, who became known as the National Volunteers, rather than fight for Britain in the war.[21] Many of the National Volunteers did enlist, and the majority of the men in the 16th (Irish) Division of the British Army had formerly served in the National Volunteers.[22] The Irish Volunteers and the Irish Citizen Army launched the Easter Rising against British rule in 1916, when an Irish Republic was proclaimed. Thereafter they became known as the Irish Republican Army (IRA). Between 1919–21 the IRA claimed to have a total strength of 70,000, but only about 3,000 were actively engaged in fighting against the Crown.[23] The IRA distrusted those Irishmen who had fought in the British Army during the First World War, but there were a number of exceptions such as Emmet Dalton, Tom Barry and Martin Doyle.[23] The basic structure of the IRA was the "flying column" which could number between 20 and 100 men.[23] Finally, Michael Collins created the "Squad"—gunmen responsible to himself who were assigned special duties such as the assassination of policemen and suspected informers within the IRA.[23]
Course of the war

Pre-war violence
The years between the Easter Rising of 1916 and the beginning of the War of Independence in 1919 were not bloodless. Thomas Ashe, one of the Volunteer leaders imprisoned for his role in the 1916 rebellion, died on hunger strike, after attempted force-feeding in 1917. In 1918, during disturbances arising out of the anti-conscription campaign, six civilians died in confrontations with the police and British Army and over 1,000 were arrested. Armistice Day was marked by severe rioting in Dublin, which left over 100 British soldiers injured.[24] There were also raids for arms by the Volunteers,[25] at least one shooting of a Royal Irish Constabulary (RIC) policeman and the burning of an RIC barracks in Kerry.[26] In Co. Cork, four rifles were seized from the Eyeries barracks in March 1918 and men from the barracks were beaten that August.[27] In early July 1918, Volunteers ambushed two RIC men who had been stationed to stop a feis being held on the road between Ballingeary and Ballyvourney in the first armed attack on the RIC since the Easter Rising – one was shot in the neck, the other beaten, and police carbines and ammunition were seized.[27][28][29] Patrols in Bantry and Ballyvourney were badly beaten in September and October. The attacks brought a British military presence from the summer of 1918, which only briefly quelled the violence, and an increase in police raids.[27] However, there was as yet no co-ordinated armed campaign against British forces or RIC.
Initial hostilities

While it was not clear in the beginning of 1919 that the Dáil ever intended to gain independence by military means, and war was not explicitly threatened in Sinn Féin's 1918 manifesto,[30][31] an incident occurred on 21 January 1919, the same day as the First Dáil convened.  The Soloheadbeg Ambush, in County Tipperary, was led by Seán Treacy, Séumas Robinson, Seán Hogan and Dan Breen acting on their own initiative. The IRA attacked and shot two RIC officers, Constables James McDonnell and Patrick O'Connell,[32] who were escorting explosives. Breen later recalled:
...we took the action deliberately, having thought over the matter and talked it over between us. Treacy had stated to me that the only way of starting a war was to kill someone, and we wanted to start a war, so we intended to kill some of the police whom we looked upon as the foremost and most important branch of the enemy forces. The only regret that we had following the ambush was that there were only two policemen in it, instead of the six we had expected.[33]

This is widely regarded as the beginning of the War of Independence.[34][35][36][37] The British government declared South Tipperary a Special Military Area under the Defence of the Realm Act two days later.[38][39] The war was not formally declared by the Dáil until well into the conflict, however. On 10 April 1919 the Dáil was told: As regards the Republican prisoners, we must always remember that this country is at war with England and so we must in a sense regard them as necessary casualties in the great fight.[40] In January 1921, two years after the war had started, the Dáil debated "whether it was feasible to accept formally a state of war that was being thrust on them, or not", and decided not to declare war.[41] Then on 11 March, Dáil Éireann President Éamon de Valera formally 'accepted' the existence of a "state of war with England".[42][43] The delay allowed a balancing of the military and political realities.
Violence spreads

Volunteers began to attack British government property, carry out raids for arms and funds and target and kill prominent members of the British administration. The first was Resident Magistrate John C. Milling, who was shot dead in Westport, County Mayo, for having sent Volunteers to prison for unlawful assembly and drilling.[44] They mimicked the successful tactics of the Boers' fast violent raids without uniform. 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 Michael Collins and the broader IRA leadership opposed these tactics as they had led to the military débacle of 1916. Others, notably Arthur Griffith, preferred a campaign of civil disobedience rather than armed struggle.[45] The violence used was at first deeply unpopular with Irish people and it took the heavy-handed British response to popularise it among much of the population.[46]

During the early part of the conflict, roughly from 1919 to the middle of 1920, there was a relatively limited amount of violence. Much of the nationalist campaign involved popular mobilisation and the creation of a republican "state within a state" in opposition to British rule. British journalist Robert Lynd wrote in The Daily News in July 1920 that: So far as the mass of people are concerned, the policy of the day is not active but a passive policy. Their policy is not so much to attack the Government as to ignore it and to build up a new government by its side.[47]
Royal Irish Constabulary (RIC) as special target

The IRA's main target throughout the conflict was the mainly Irish Catholic Royal Irish Constabulary (RIC), the British government's police in Ireland, outside Dublin. Its members and barracks (especially the more isolated ones) were vulnerable, and they were a source of much-needed arms. The RIC numbered 9,700 men stationed in 1,500 barracks throughout Ireland.[48]
A policy of ostracism of RIC men was announced by the Dáil on 11 April 1919.[49] This proved successful in demoralising the force as the war went on, as people turned their faces from a force increasingly compromised by association with British government repression.[50] The rate of resignation went up and recruitment in Ireland dropped off dramatically. Often, the RIC were reduced to buying food at gunpoint, as shops and other businesses refused to deal with them. Some RIC men co-operated with the IRA through fear or sympathy, supplying the organisation with valuable information. By contrast with the effectiveness of the widespread public boycott of the police, the military actions carried out by the IRA against the RIC at this time were relatively limited. In 1919, 11 RIC men and 4 Dublin Metropolitan Police G Division detectives were killed and another 20 RIC wounded.[51]
Other aspects of mass participation in the conflict included strikes by organised workers, in opposition to the British presence in Ireland. In Limerick in April 1919, a general strike was called by the Limerick Trades and Labour Council, as a protest against the declaration of a "Special Military Area" under the Defence of the Realm Act, which covered most of Limerick city and a part of the county. Special permits, to be issued by the RIC, would now be required to enter the city. The Trades Council's special Strike Committee controlled the city for fourteen days in an episode that is known as the Limerick Soviet.[52]
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. Blackleg train drivers were brought over from England, after drivers refused to carry British troops. The strike badly hampered British troop movements until December 1920, when it was called off.[53] The British government managed to bring the situation to an end, when they threatened to withhold grants from the railway companies, which would have meant that workers would no longer have been paid.[54] Attacks by the IRA also steadily increased, and by early 1920, they were attacking isolated RIC stations in rural areas, causing them to be abandoned as the police retreated to the larger towns.
Collapse of the British administration
In early April 1920, 400 abandoned RIC barracks were burned to the ground to prevent them being used again, along with almost one hundred income tax offices. The RIC withdrew from much of the countryside, leaving it in the hands of the IRA.[55] In June–July 1920, assizes failed all across the south and west of Ireland; trials by jury could not be held because jurors would not attend. The collapse of the court system demoralised the RIC and many police resigned or retired. The Irish Republican Police (IRP) was founded between April and June 1920, under the authority of Dáil Éireann and the former IRA Chief of Staff Cathal Brugha to replace the RIC and to enforce the ruling of the Dáil Courts, set up under the Irish Republic. By 1920, the IRP had a presence in 21 of Ireland's 32 counties.[56] The Dáil Courts were generally socially conservative, despite their revolutionary origins, and halted the attempts of some landless farmers at redistribution of land from wealthier landowners to poorer farmers.[57]
The Inland Revenue ceased to operate in most of Ireland. People were instead encouraged to subscribe to Collins' "National Loan", set up to raise funds for the young government and its army. By the end of the year the loan had reached £358,000. It eventually reached £380,000. An even larger amount, totalling over $5 million, was raised in the United States by Irish Americans and sent to Ireland to finance the Republic.[54] Rates were still paid to local councils but nine out of eleven of these were controlled by Sinn Féin, who naturally refused to pass them on to the British government.[57] By mid-1920, the Irish Republic was a reality in the lives of many people, enforcing its own law, maintaining its own armed forces and collecting its own taxes. The British Liberal journal, The Nation, wrote in August 1920 that "the central fact of the present situation in Ireland is that the Irish Republic exists".[47]
The British forces, in trying to re-assert their control over the country, often resorted to arbitrary reprisals against republican activists and the civilian population. An unofficial government policy of reprisals began in September 1919 in Fermoy, County Cork, when 200 British soldiers looted and burned the main businesses of the town, after one of their number – a soldier of the King's Shropshire Light Infantry who was the first British Army death in the campaign – had been killed in an armed raid by the local IRA[58] on a church parade the day before (7 September).  The ambushers were a unit of the No 2 Cork Brigade, under command of Liam Lynch, who wounded four of the other soldiers and disarmed the rest before fleeing in their cars. The local coroner's inquest refused to return a murder verdict over the soldier and local businessmen who had sat on the jury were targeted in the reprisal.[59]
Arthur Griffith estimated that in the first 18 months of the conflict, British forces carried out 38,720 raids on private homes, arrested 4,982 suspects, committed 1,604 armed assaults, carried out 102 indiscriminate shootings and burnings in towns and villages, and killed 77 people including women and children.[60] 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. Swanzy was later tracked down and killed in Lisburn, County Antrim. This pattern of killings and reprisals escalated in the second half of 1920 and in 1921.[61]
IRA organisation and operations

Michael Collins was a driving force behind the independence movement. Nominally the Minister of Finance in the republic's government and IRA Director of Intelligence, he was involved in providing funds and arms to the IRA units and in the selection of officers. Collins' charisma and organisational capability galvanised many who came in contact with him. He established what proved an effective network of spies among sympathetic members of the Dublin Metropolitan Police's (DMP) G Division  and other important branches of the British administration. The G Division men were a relatively small political division active in subverting the republican movement and were detested by the IRA as often they were used to identify volunteers, who would have been unknown to British soldiers or the later Black and Tans. Collins set up the "Squad", a group of men whose sole duty was to seek out and kill "G-men" and other British spies and agents. Collins' Squad began killing RIC intelligence officers in July 1919.[62] Many G-men were offered a chance to resign or leave Ireland by the IRA. 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.[63]
The Chief of Staff of the IRA was Richard Mulcahy, who was responsible for organising and directing IRA units around the country. In theory, both Collins and Mulcahy were responsible to Cathal Brugha, the Dáil's Minister of Defence, but, in practice, Brugha had only a supervisory role, recommending or objecting to specific actions. A great deal also depended on IRA leaders in local areas (such as Liam Lynch, Tom Barry, Seán Moylan, Seán Mac Eoin and Ernie O'Malley) who organised guerrilla activity, largely on their own initiative. For most of the conflict, IRA activity was concentrated in Munster and Dublin, with only isolated active IRA units elsewhere, such as in County Roscommon, north County Longford and western County Mayo.
While the paper membership of the IRA, carried over from the Irish Volunteers, was over 100,000 men, Michael Collins estimated that only 15,000 were active in the IRA during the course of the war, with about 3,000 on active service at any time. There were also support organisations Cumann na mBan (the IRA women's group) and Fianna Éireann (youth movement), who carried weapons and intelligence for IRA men and secured food and lodgings for them. The IRA benefitted from the widespread help given to them by the general Irish population, who generally refused to pass information to the RIC and the British military and who often provided "safe houses" and provisions to IRA units "on the run". Much of the IRA's popularity arose from the excessive reaction of the British forces to IRA activity. When Éamon de Valera returned from the United States, he demanded in the Dáil that the IRA desist from the ambushes and assassinations, which were allowing the British to portray it as a terrorist group and to take on the British forces with conventional military methods. The proposal was immediately dismissed.
Martial law

The British increased the use of force; reluctant to deploy the regular British Army into the country in greater numbers, they set up two paramilitary police units to aid the RIC. The Black and Tans were seven thousand strong, mainly ex-British soldiers demobilised after World War I. Deployed to Ireland in March 1920, most came from English and Scottish cities.  While officially they were part of the RIC, in reality they were a paramilitary force. After their deployment in March 1920, they rapidly gained a reputation for drunkenness and ill discipline, that did more harm to the British government's moral authority in Ireland than any other group. In response to IRA actions, in the summer of 1920, the Tans burned and sacked numerous small towns throughout Ireland, including Balbriggan, Trim, Templemore and others.
In July 1920, another quasi-military police body, the Auxiliaries, consisting of 2,215 former British army officers, arrived in Ireland. The Auxiliary Division had a reputation just as bad as the Tans for their mistreatment of the civilian population but tended to be more effective and more willing to take on the IRA. The policy of reprisals, which involved public denunciation or denial and private approval, was famously satirised by Lord Hugh Cecil when he said: "It seems to be agreed that there is no such thing as reprisals but they are having a good effect."[64]
On 9 August 1920, the British Parliament passed the Restoration of Order in Ireland Act. It replaced the trial by jury by courts-martial by regulation for those areas where IRA activity was prevalent.[65] On 10 December 1920, martial law was proclaimed in Counties Cork, Kerry, Limerick and Tipperary in Munster; in January 1921 martial law was extended to the rest of Munster in Counties Clare and Waterford, as well as Counties Kilkenny and Wexford in Leinster.[66] It also suspended all coroners' courts because of the large number of warrants served on members of the British forces and replaced them with "military courts of enquiry".[67] The powers of military courts-martial were extended to cover the whole population and were empowered to use the death penalty and internment without trial; Government payments to local governments in Sinn Féin hands were suspended. This act has been interpreted by historians as a choice by Prime Minister David Lloyd George to put down the rebellion in Ireland rather than negotiate with the republican leadership.[68] As a result, violence escalated steadily from that summer and sharply after November 1920 until July 1921. (It was in this period that a mutiny broke out among the Connaught Rangers, stationed in India. Two were killed whilst trying to storm an armoury and one was later executed.)[69]
Escalation: October–December 1920

A number of events dramatically escalated the conflict in late 1920. First the Lord Mayor of Cork, Terence MacSwiney, died on hunger strike in Brixton Prison in London in October, while two other IRA prisoners on hunger strike, Joe Murphy and Michael Fitzgerald, died in Cork Jail.
Then, on 21 November 1920, there was a day of dramatic bloodshed in Dublin. In the early morning, Collins' Squad attempted to wipe out the leading British intelligence operatives in the capital. The Squad shot 19 people, killing 14 and wounding 5. These consisted of British Army officers, police officers and civilians. The dead included members of the Cairo Gang and a courts-martial officer, and were killed at different places around Dublin.
In response, RIC men drove in trucks into Croke Park (Dublin's GAA football and hurling ground) during a football match, shooting into the crowd. Fourteen civilians were killed, including one of the players, Michael Hogan, and a further 65 people were wounded.[70] Later that day two republican prisoners, Dick McKee, Peadar Clancy and an unassociated friend, Conor Clune who had been arrested with them, were killed in Dublin Castle. The official account was that the three men were shot "while trying to escape", which was rejected by Irish nationalists, who were certain the men had been tortured then murdered.[71][72] This day became known as Bloody Sunday.
On 28 November 1920, only a week after Bloody Sunday in Dublin, the west Cork unit of the IRA, under Tom Barry, ambushed a patrol of Auxiliaries at Kilmichael in County Cork, killing all but one of the 18-man patrol.
These actions marked a significant escalation of the conflict. In response, Counties Cork, Kerry, Limerick, and Tipperary – all in the province of Munster – were put under martial law on 10 December under the Restoration of Order in Ireland Act; this was followed on 5 January in the rest of Munster and in Counties Kilkenny and Wexford in the province of Leinster.[66] Shortly afterwards, in January 1921, "official reprisals" were sanctioned by the British and they began with the burning of seven houses in Midleton in Cork.

On 11 December, the centre of Cork City was burnt out by the Black and Tans, who then shot at firefighters trying to tackle the blaze, in reprisal for an IRA ambush in the city on 11 December 1920 which killed one Auxiliary and wounded eleven.[73]
Attempts at a truce in December 1920 were scuppered by Hamar Greenwood, who insisted on a surrender of IRA weapons first.[74]
Peak of violence: December 1920 – July 1921
During the following eight months until the Truce of July 1921, there was a spiralling of the death toll in the conflict, with 1,000 people including the RIC police, army, IRA volunteers and civilians, being killed in the months between January and July 1921 alone.[75] This represents about 70% of the total casualties for the entire three-year conflict. In addition, 4,500 IRA personnel (or suspected sympathisers) were interned in this time.[76] In the middle of this violence, the Dáil formally declared war on Britain in March 1921.
Between 1 November 1920 and 7 June 1921 twenty-four men were executed by the British.[77] The first IRA volunteer to be executed was Kevin Barry, one of The Forgotten Ten who were buried in unmarked graves in unconsecrated ground inside Mountjoy Prison until 2001.[78] On 1 February, the first execution under martial law of an IRA man took place. Cornelius Murphy of Millstreet, Cork was shot in Cork city. On 28 February, six more were executed, again in Cork.
On 19 March 1921, Tom Barry's 100-strong West Cork IRA unit fought an action against 1,200 British troops – the Crossbarry Ambush. Barry's men narrowly avoided being trapped by converging British columns and inflicted between ten and thirty killed on the British side. Just two days later, on 21 March, the Kerry IRA attacked a train at the Headford junction near Killarney. Twenty British soldiers were killed or injured, as well as two IRA men and three civilians. 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 Carowkennedy in Mayo in May and June. Equally common, however, were failed ambushes, the worst of which, for example at Upton and Clonmult in Cork in February 1921, saw three and twelve IRA men killed respectively and more captured. The IRA in Mayo suffered a comparable reverse at Kilmeena, while the Leitrim flying column was almost wiped out at Selton Hill. Fears of informers after such failed ambushes often led to a spate of IRA shootings of informers, real and imagined.
The biggest single loss for the IRA, however, came in Dublin. On 25 May 1921, several hundred IRA men from the Dublin Brigade occupied and burned the Custom House (the centre of local government in Ireland) in Dublin city centre. Symbolically, this was intended to show that British rule in Ireland was untenable. However, from a military point of view, it was a heavy defeat in which five IRA men were killed and over eighty captured.[79] This showed the IRA was not well enough equipped or trained to take on British forces in a conventional manner. However, it did not, as is sometimes claimed, cripple the IRA in Dublin. The Dublin Brigade carried out 107 attacks in the city in May and 93 in June, showing a falloff in activity, but not a dramatic one. However, by July 1921, most IRA units were chronically short of both weapons and ammunition, with over 3,000 prisoners interned.[80] Also, for all their effectiveness at guerrilla warfare, they had, as Richard Mulcahy recalled, "as yet not been able to drive the enemy out of anything but a fairly good sized police barracks".[81]
Still, many military historians have concluded that the IRA fought a largely successful and lethal guerrilla war, which forced the British government to conclude that the IRA could not be defeated militarily.[82] The failure of the British efforts to put down the guerrillas was illustrated by the events of "Black Whitsun" on 13–15 May 1921.  A general election for the Parliament of Southern Ireland was held on 13 May. Sinn Féin won 124 of the new parliament's 128 seats unopposed, but its elected members refused to take their seats. Under the terms of the Government of Ireland Act 1920, the Parliament of Southern Ireland was therefore dissolved, and executive and legislative authority over Southern Ireland was effectively transferred to the Lord Lieutenant (assisted by Crown appointees).  Over the next two days (14–15 May), the IRA killed fifteen policemen. These events marked the complete failure of the British Coalition Government's Irish policy—both the failure to enforce a settlement without negotiating with Sinn Féin and a failure to defeat the IRA.
By the time of the truce, however, many republican leaders, including Michael Collins, were convinced that if the war went on for much longer, there was a chance that the IRA campaign as it was then organised could be brought to a standstill. Because of this, plans were drawn up to "bring the war to England". The IRA did take the campaign to the streets of Glasgow.[83] It was decided that key economic targets, such as the Liverpool docks, would be bombed. The units charged with these missions would more easily evade capture because England was not under, and British public opinion was unlikely to accept, martial law. These plans were abandoned because of the truce.

Truce: July–December 1921

The war of independence in Ireland ended with a truce on 11 July 1921. The conflict had reached a stalemate. Talks that had looked promising the previous year had petered out in December when David Lloyd George insisted that the IRA first surrender their arms. Fresh talks, after the Prime Minister had come under pressure from Herbert Henry Asquith and the Liberal opposition, the Labour Party and the Trades Union Congress, resumed in the spring and resulted in the Truce. From the point of view of the British government, it appeared as if the IRA's guerrilla campaign would continue indefinitely, with spiralling costs in British casualties and in money. More importantly, the British government was facing severe criticism at home and abroad for the actions of British forces in Ireland. On 6 June 1921, the British made their first conciliatory gesture, calling off the policy of house burnings as reprisals. On the other side, IRA leaders and in particular Michael Collins, felt that the IRA as it was then organised could not continue indefinitely. It had been hard pressed by the deployment of more regular British soldiers to Ireland and by the lack of arms and ammunition.
The initial breakthrough that led to the truce was credited to three people: King George V, Prime Minister of South Africa General Jan Smuts and Prime Minister of the United Kingdom David Lloyd George. The King, who had made his unhappiness at the behaviour of the Black and Tans in Ireland well known to his government, was dissatisfied with the official speech prepared for him for the opening of the new Parliament of Northern Ireland, created as a result of the partition of Ireland. Smuts, a close friend of the King, suggested to him that the opportunity should be used to make an appeal for conciliation in Ireland. The King asked him to draft his ideas on paper. Smuts prepared this draft and gave copies to the King and to Lloyd George. Lloyd George then invited Smuts to attend a British cabinet meeting consultations on the "interesting" proposals Lloyd George had received, without either man informing the Cabinet that Smuts had been their author. Faced with the endorsement of them by Smuts, the King and the Prime Minister, ministers reluctantly agreed to the King's planned 'reconciliation in Ireland' speech.
The speech, when delivered in Belfast on 22 June, was universally well received. 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."[84]
On 24 June 1921, the British Coalition Government's Cabinet decided to propose talks with the leader of Sinn Féin. Coalition Liberals and Unionists agreed that an offer to negotiate would strengthen the Government's position if Sinn Féin refused. Austen Chamberlain, the new leader of the Unionist Party, said that "the King's Speech ought to be followed up as a last attempt at peace before we go the full lengths of martial law".[85] 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.[86] Sinn Féin responded by agreeing to talks. De Valera and Lloyd George ultimately agreed to a truce that was intended to end the fighting and lay the ground for detailed negotiations. Its terms were signed on 9 July and came into effect on 11 July. Negotiations on a settlement, however, were delayed for some months as the British government insisted that the IRA first decommission its weapons, but this demand was eventually dropped. It was agreed that British troops would remain confined to their barracks.
Most IRA officers on the ground interpreted the Truce merely as a temporary respite and continued recruiting and training volunteers. Nor did attacks on the RIC or British Army cease altogether. Between December 1921 and February of the next year, there were 80 recorded attacks by the IRA on the soon to be disbanded RIC, leaving 12 dead.[87] 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.[88] In April 1922, in the Dunmanway killings, an IRA party in Cork killed 10 local suspected Protestant informers in retaliation for the shooting of one of their men. Those killed were named in captured British files as informers before the Truce signed the previous July.[89] Over 100 Protestant families fled the area after the killings.
The continuing resistance of many IRA leaders was one of the main factors in the outbreak of the Irish Civil War as they refused to accept the Anglo-Irish Treaty that Michael Collins and Arthur Griffith had negotiated with the British.

Treaty

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.[90][91][92]
The treaty allowed Northern Ireland, which had been created by the Government of Ireland Act 1920, to opt out of the Free State if it wished, which it duly did on 8 December 1922 under the procedures laid down. As agreed, an Irish Boundary Commission was then created to decide on the precise location of the border of the Free State and Northern Ireland.[93]  The republican negotiators understood that the Commission would redraw the border according to local nationalist or unionist majorities.  Since the 1920 local elections in Ireland had resulted in outright nationalist majorities in County Fermanagh, County Tyrone, the City of Derry and in many District Electoral Divisions of County Armagh and County Londonderry (all north and west of the "interim" border), this might well have left Northern Ireland unviable. However, the Commission chose to leave the border unchanged; as a trade-off, the money owed to Britain by the Free State under the Treaty was not demanded.
A new system of government was created for the new Irish Free State, though for the first year two governments co-existed; an Aireacht answerable to the Dáil and headed by President Griffith, and a Provisional Government nominally answerable to the House of Commons of Southern Ireland and appointed by the Lord Lieutenant.[94]
Most of the Irish independence movement's leaders were willing to accept this compromise, at least for the time being, though many militant republicans were not.  A majority 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. It also broke the Oath of Allegiance to the Irish Republic which the Dáil had instated on 20 August 1919.[95] The anti-treaty IRA were supported by the former president of the Republic, Éamon de Valera, and ministers Cathal Brugha and Austin Stack.[96]

While the violence in the North was still raging, the South of Ireland was preoccupied with the split in the Dáil and in the IRA over the treaty. In April 1922, an executive of IRA officers repudiated the treaty and the authority of the Provisional Government which had been set up to administer it. These republicans held that the Dáil did not have the right to disestablish 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. There were a number of armed confrontations between pro and anti-treaty troops before matters came to a head in late June 1922.[92] Desperate to get the new Irish Free State off the ground and under British pressure, Michael Collins attacked the anti-treaty militants in Dublin, causing fighting to break out around the country.[92]
The subsequent Irish Civil War lasted until mid-1923 and cost the lives of many of the leaders of the independence movement, notably the head of the Provisional Government Michael Collins, ex-minister Cathal Brugha, and anti-treaty republicans Harry Boland, Rory O'Connor, Liam Mellows, Liam Lynch and many others: total casualties have never been determined but were perhaps higher than those in the earlier fighting against the British. President Arthur Griffith also died of a cerebral haemorrhage during the conflict.[97]
Following the deaths of Griffith and Collins, W. T. Cosgrave became head of government. On 6 December 1922, following the coming into legal existence of the Irish Free State, W. T. Cosgrave became President of the Executive Council, the first internationally recognised head of an independent Irish government.
The civil war ended in mid-1923 in defeat for the anti-treaty side.[98]
North-east

In the Government of Ireland Act 1920 (enacted in December 1920), the British government attempted to solve the conflict by creating two Home Rule parliaments in Ireland: Northern Ireland and Southern Ireland. While Dáil Éireann ignored this, deeming the Irish Republic to be already in existence, Unionists in the north-east accepted it and prepared to form their own government. In this part of Ireland, which was predominantly Protestant and Unionist, there was, as a result, a very different pattern of violence from the rest of the country. Whereas in the south and west, the conflict was between the IRA and British forces, in the north-east and particularly in Belfast, it often developed into a cycle of sectarian killings between Catholics, who were largely Nationalist, and Protestants, who were mostly Unionist.
Summer 1920
While IRA attacks were less common in the north-east than elsewhere, the unionist community saw itself as being besieged by armed Catholic nationalists who seemed to have taken over the rest of Ireland. As a result, they retaliated against the northern Catholic community as a whole. Such action was largely condoned by the unionist leadership and abetted by state forces. James Craig, for instance, wrote in 1920: The Loyalist rank and file have determined to take action... they 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.[99]
The first cycle of attacks and reprisals broke out in the summer of 1920. On 19 June a week of inter-sectarian rioting and sniping started in Derry, resulting in 18 deaths.[100] On 17 July 1920, a British Colonel Gerald Smyth was assassinated by the IRA in the County Club in Cork city in response to a speech that was made to police officers of Listowel who had refused orders to move into the more urban areas, in which he stated "you may make mistakes occasionally, and innocent persons may be shot, but that cannot be helped. No policeman will get in trouble for shooting any man".[101][102] Smyth came from Banbridge, County Down in the north-east and his killing provoked retaliation there against Catholics in Banbridge and Dromore. On 21 July 1920, partly in response to the killing of Smyth and partly because of competition over jobs due to the high unemployment rate, loyalists marched on the Harland and Wolff shipyards in Belfast and forced over 7,000 Catholic and left-wing Protestant workers from their jobs. Sectarian rioting broke out in response in Belfast and Derry, resulting in about 40 deaths and many Catholics and Protestants being expelled from their homes. On 22 August 1920, RIC Detective Swanzy was shot dead by Cork IRA men while leaving church in Lisburn, County Antrim. Swanzy had been blamed by an inquest jury for the killing of Cork Mayor Tomás Mac Curtain. In revenge, local Loyalists burned Catholic residential areas of Lisburn – destroying over 300 homes. While several people were later prosecuted for the burnings, no attempt seems to have been made to halt the attacks at the time. Michael Collins, acting on a suggestion by Seán MacEntee, organised a boycott of Belfast goods in response to the attacks on the Catholic community. The Dáil approved a partial boycott on 6 August and a more complete one was implemented by the end of 1920.
Spring 1921
After a lull in violence in the north over the new year, killings there intensified again in the spring of 1921. The northern IRA units came under pressure from the leadership in Dublin to step up attacks in line with the rest of the country. Predictably, this unleashed loyalist reprisals against Catholics. For example, in April 1921, the IRA in Belfast shot dead two Auxiliaries in Donegal Place in Belfast city centre. The same night, two Catholics were killed on the Falls Road. On 10 July 1921 the IRA ambushed British forces in Raglan street in Belfast. In the following week, sixteen Catholics were killed and 216 Catholic homes burned in reprisal – events known as Belfast's Bloody Sunday.
Killings on the loyalist side were largely carried out by the Ulster Volunteer Force (UVF), allegedly with the aid of the RIC and especially the auxiliary police force, the Ulster Special Constabulary or "B-Specials". The Special Constabulary (set up in September 1920), was largely recruited from Ulster Volunteer Force and Orange Lodges and, in the words of historian Michael Hopkinson, "amounted to an officially approved UVF".[103] In May James Craig came to Dublin to meet the British Lord Lieutenant of Ireland, Lord FitzAlan, and was smuggled by the IRA through Dublin to meet Éamon de Valera. The two leaders discussed the possibility of a truce in Ulster and an amnesty for prisoners. Craig proposed a compromise settlement based on the Government of Ireland Act, 1920, with limited independence for the South and autonomy for the North within a Home Rule context. However, the talks came to nothing and violence in the north continued.[104]
July 1921 – May 1922
While the fighting in the south was largely ended by the Truce on 11 July 1921, in the north killings continued and actually escalated until the summer of 1922. In Belfast, 16 people were killed in the two days after the truce alone. The violence in the city took place in bursts, as attacks on both Catholics and Protestants were rapidly followed by reprisals on the other community. In this way, 20 people died in street fighting and assassinations in north and west Belfast over 29 August to 1 September 1921 and another 30 from 21–25 November. Loyalists had by this time taken to firing and throwing bombs randomly into Catholic areas and the IRA responded by bombing trams which took Protestant workers to their places of employment.[105]
Moreover, 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. In part, this reflected Michael Collins' view that the Treaty was a tactical move, or "stepping stone", rather than a final settlement. A number of IRA men were arrested in Derry when they travelled there as part of the Monaghan Gaelic football team. In retaliation, Michael Collins had forty-two loyalists taken hostage in Fermanagh and Tyrone. Right after this incident, a group of B-Specials were confronted by an IRA unit at Clones in Southern territory, who demanded that they surrender. The IRA unit's leader was shot dead and a gun battle broke out, in which four Special Constables were killed. The withdrawal of British troops from Ireland was temporarily suspended as a result of this event. Despite the setting up of a Border Commission to mediate between the two sides in late February, the IRA raided three British barracks along the border in March. All of these actions provoked retaliatory killings in Belfast. In the two days after the Fermanagh kidnappings, 30 people lost their lives in the city, including four Catholic children and two women who were killed by a Loyalist bomb on Weaver Street.  In March, 60 died in Belfast, including six members of the Catholic McMahon family, who were targeted for assassination by members of the Special Constabulary in revenge for the IRA killing of two policemen (See McMahon murders).[106] In April, another 30 people died in the Northern capital, including another so called 'uniform attack', the Arnon Street Massacre, when six Catholics were killed by uniformed policemen.[107]
Winston Churchill arranged a meeting between Collins and James Craig on 21 January 1922 and the southern boycott of Belfast goods was lifted but then re-imposed after several weeks. The two leaders had several further meetings, but despite a joint declaration that "Peace is declared" on 30 March, the violence continued.[108]
May–June 1922
In May and June 1922, Collins launched a guerrilla IRA offensive against Northern Ireland. By this time, the IRA was split over the Anglo-Irish Treaty, but both pro and anti-treaty units were involved in the operation. Some of the arms sent by the British to arm the new Irish Army were in fact given to IRA units and their weapons sent to the North.[109] However, the offensive, launched with a series of IRA attacks in the North on 17–19 May, ultimately proved a failure. An IRA Belfast Brigade report in late May concluded that continuing the offensive was "futile and foolish...the only result of the attack was to place the Catholic population at the mercy of the Specials".[110]
On 22 May, after the assassination of West Belfast Unionist MP William Twaddell, 350 IRA men were arrested in Belfast, crippling its organisation there.[111] The largest single clash came in June, when British troops used artillery to dislodge an IRA unit from the village of Pettigo, killing seven, wounding six and taking four prisoners. This was the last major confrontation between the IRA and British forces in the period 1919–1922.[112] The cycle of sectarian atrocities against civilians however continued into June 1922. May saw 75 people killed in Belfast and another 30 died there in June. Several thousand Catholics fled the violence and sought refuge in Glasgow and Dublin.[113] On 17 June, in revenge for the killing of two Catholics by the B-Specials, Frank Aiken's IRA unit shot ten Protestant civilians, killing six in and around Altnaveigh, south Armagh. Three Special Constables were also killed in the shootings.[114]
Michael Collins held the British Field Marshal Sir Henry Wilson (by then MP for North Down) responsible for the attacks on Catholics in the north and may have been behind his assassination in June 1922, though who ordered the shooting is unproven.[115] The event helped to trigger the Irish Civil War. Winston Churchill insisted after the killing that Collins take action against the Anti-Treaty IRA, whom he assumed to be responsible.[116] The outbreak of the civil war in the South ended the violence in the North, as the war demoralised the IRA in the north east and distracted the attention of the rest of the organisation from the question of partition. After Collins' death in August 1922, the new Irish Free State quietly ended Collins' policy of covert armed action in Northern Ireland.
The violence in the north fizzled out by late 1922, the last reported killing of the conflict in what was now Northern Ireland took place on 5 October.[117]
Detention
During the 1920s, the vessel HMS<i>Argenta was used as a military base and prison ship for the holding of Irish Republicans by the British government as part of their internment strategy after Bloody Sunday. Cloistered below decks in cages which held 50 internees, the prisoners were forced to use broken toilets which overflowed frequently into their communal area. Deprived of tables, the already weakened men ate off the floor, frequently succumbing to disease and illness as a result.  There were several hunger strikes, including a major strike involving upwards of 150 men in the winter of 1923.[118]
By February 1923, under the 1922 Special Powers Act the British were detaining 263 men on Argenta, which was moored in Belfast Lough. This was supplemented with internment at other land based sites such as Larne workhouse, Belfast Prison and Derry Gaol. Together, both the ship and the workhouse alone held 542 men without trial at the highest internment population level during June 1923.[118]
Propaganda war

Another feature of the war was the use of propaganda by both sides.[119] In the summer of 1921, a series of articles appeared in a London magazine, entitled "Ireland under the New Terror, Living Under Martial Law". While purporting to be an impartial account of the situation in Ireland, it portrayed the IRA in a very unfavourable light when compared with the British forces. In reality the author, Ernest Dowdall, was an Auxiliary and the series was one of many articles planted by the Dublin Castle Propaganda Department (established in August 1920) to influence public opinion in a Britain increasingly dismayed at the behaviour of its security forces in Ireland.[120]
The British government also collected material on the liaison between Sinn Féin and Soviet Russia, in an unsuccessful attempt to portray Sinn Féin as a crypto-communist movement.[121]
The Catholic Church hierarchy was critical of the violence of both sides, but especially that of the IRA, continuing a long tradition of condemning militant republicanism. The Bishop of Kilmore, Dr. Finnegan, said: "Any war... to be just and lawful must be backed by a well grounded hope of success. What hope of success have you against the mighty forces of the British Empire? None... none whatever and if it unlawful as it is, every life taken in pursuance of it is murder."[122] 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."[123] However, in May 1921, Pope Benedict XV dismayed the British government when he issued a letter that exhorted the "English as well as Irish to calmly consider . . . some means of mutual agreement", as they had been pushing for a condemnation of the rebellion.[124] They declared that his comments "put HMG (His Majesty's Government) and the Irish murder gang on a footing of equality".[124]
Desmond FitzGerald and Erskine Childers were active in producing the Irish Bulletin, which detailed government atrocities which Irish and British newspapers were unwilling or unable to cover. It was printed secretly and distributed throughout Ireland, and to international press agencies and US, European and sympathetic British politicians.

While the military war made most of Ireland ungovernable from early 1920, it did not actually remove British forces from any part. But the success of Sinn Féin's propaganda campaign reduced the option of the British government to deepen the conflict; it worried in particular about the effect on British relations with the US, where groups like the American Committee for Relief in Ireland had so many eminent members. The British cabinet had not sought the war that had developed since 1919. By 1921 one of its members, Winston Churchill, reflected: What was the alternative? It was to plunge one small corner of the empire into an iron repression, which could not be carried out without an admixture of murder and counter-murder.... Only national self-preservation could have excused such a policy, and no reasonable man could allege that self-preservation was involved.[125]
Casualties

The total number killed in the guerrilla war of 1919–21 between republicans and British forces in what became the Irish Free State came to over 1,400. Of these, 363 were police personnel, 261 were from the regular British Army, about 550 were IRA volunteers (including 24 official executions), and about 200 were civilians.[1][77] Some other sources give higher figures.[126]
On 21 November 1921 the British army held a memorial service for its dead, of all ranks, of which it counted 162 up to the 1921 Truce and 18 killed afterwards.[127] A number of these are buried in the Grangegorman Military Cemetery.[128]
557 people died in political violence in what would become Northern Ireland between July 1920 and July 1922. This death toll is usually counted separately  from the southern casualties, as many of these deaths took place after the 11 July truce that ended fighting in the rest of Ireland. Of these deaths, between 303 and 340 were Catholic civilians, 35 were IRA men, between 172 and 196 were Protestant civilians and 82 were British forces personnel (38 were RIC and 44 were Ulster Special Constables). The majority of the violence took place in Belfast: 452 people were killed there – 267 Catholics and 185 Protestants.[129]
Irish nationalists have argued that this northern violence represented a pogrom against their community as 58% of the victims were Catholics, even though Catholics were only around 35% of the population. Historian of the period Alan Parkinson has suggested that the term 'pogrom' is 'unhelpful and misleading in explaining the events of the period' as the violence was not state directed or one sided.[130]
Similarly in recent decades, attention has been drawn to the IRA's shooting of civilian informers in the south. Several historians, notably Peter Hart have alleged that those killed in this manner were often simply considered "enemies" rather than being proven informers. Especially vulnerable, it is argued, were Protestants, ex-soldiers and tramps. "It was not merely (or even mainly) a matter of espionage, spies and spy hunters, it was a civil war between and within communities".[131] Particularly controversial in this regard has been the Dunmanway killings of April 1922, when ten Protestants were killed and three "disappeared" over two nights. Hart's contentions have been challenged by a number of historians, notably Niall Meehan[132] and Meda Ryan.[133]
Post-war evacuation of British forces

By October 1921 the British Army in Ireland numbered 57,000 men, along with 14,200 RIC police and some 2,600 auxiliaries and Black and Tans. 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. It was a huge logistical operation, but within the month Dublin Castle and Beggars Bush Barracks were transferred to the Provisional Government. The RIC last paraded on 4 April and was formally disbanded on 31 August. By the end of May the remaining forces were concentrated in Dublin, Cork and Kildare. Tensions that led to the Irish Civil War were evident by then and evacuation was suspended. By November about 6,600 soldiers remained in Dublin at 17 locations. 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.[134]
Compensation
In May 1922 the British Government with the agreement of the Irish Provisional Government established a commission chaired by Lord Shaw of Dunfermline to examine compensation claims for material damage caused between 21 January 1919 and 11 July 1921.[135] The Irish Free State's Damage To Property (Compensation) Act, 1923 provided that only the Shaw Commission, and not the Criminal Injury Acts, could be used to claim compensation.[136] Originally, the British government paid claims from unionists and the Irish government those from nationalists; claims from "neutral" parties were shared.[137] After the 1925 collapse of the Irish Boundary Commission, the UK, Free State and Northern Ireland governments negotiated revisions to the 1921 treaty; the Free State stopped contributing to the servicing of the UK national debt, but took over full responsibility for compensation for war damage, with the fund increased by 10% in 1926.[138][139] The "Compensation (Ireland) Commission" worked until March 1926, processing thousands of claims.[137]

Role of women in the war
Although largely overshadowed by the men that took part in the conflict, women played a substantial role in the Irish War of Independence. Prior to the Easter Rising of 1916, many Nationalist women were brought together through organizations that fought for women’s suffrage in Ireland, such as the Irish Women's Franchise League founded by Hanna Sheehy-Skeffington and Margaret Cousins in 1908.[140] Many Irish suffragettes, although in favor of Irish independence, were wary of joining right-wing Nationalist groups out of fear that they would be used to obtain Irish independence but not be accorded the right to vote. However, because the Irish republican and socialist leader James Connolly’s Irish Citizen Army promoted equality between men and women, many Irish suffragettes, including Constance Markiewicz, Madeleine ffench-Mullen, and Kathleen Lynn, joined the movement and it created unification among suffragettes, socialists, and Nationalists.[141] In 1914, the primary female Nationalist group that would fight in the War of Independence, Cumann na mBan, was launched as an affiliate of the Irish Volunteers. During the Easter Rising of 1916, Cumann na mBan members participated in combat alongside the men. The women acted as dispatch carriers, traveling between Irish Volunteer Posts while being shot at by British forces. [142]After the defeat of the Irish rebel forces and the execution of James Connolly and Patrick Pearse, Éamon de Valera opposed the participation of women in combat and thus, women were downgraded to subaltern roles. Nevertheless, many women refused to give up fighting and they played an active role in the War of Independence.[143] During the conflict, women hid Nationalist fighters being sought by the British, nursed injured fighters, and gathered money to assist prisoners captured by the British. In addition, Nationalist women engaged in undercover work to setback the British war effort. Nationalist women smuggled guns, ammunition, and money to the IRA, such as Kathleen Clarke who, in her autobiography, reported “smuggling £2,000 of gold from Limerick city to Dublin for IRA leader Michael Collins.”[144] Because they sheltered wanted rebels, many women were subject to raids on their homes by British soldiers with acts of sexual violence sometimes being reported but not confirmed.[143] It is estimated that there were between 3000 and 9000 members of Cumann na mBan during the war, and in 1921, there were 800 branches located throughout the island. By the end of the war, it is estimated that less than 50 women were imprisoned by the British.[144]
Memorial
A memorial called the Garden of Remembrance was erected in Dublin in 1966, on the fiftieth anniversary of the Easter Rising. The date of signing of the truce is commemorated by the National Day of Commemoration, when all those Irish men and women who fought in wars in specific armies (e.g., the Irish unit(s) fighting in the British Army in 1916 at the Battle of the Somme) are commemorated.
The last survivor of the conflict, Dan Keating (of the IRA), died in October 2007 at the age of 105.[145]
Cultural depictions
Literature
1923 – The Shadow of a Gunman, play by Seán O'Casey
1929 – The Last September, novel by Elizabeth Bowen
1970 – Troubles, novel by J. G. Farrell
1979 – The Old Jest, novel by Jennifer Johnston, winner of the Whitbread Award
2010 – The Soldier's Song, novel by Alan Monaghan
Television and film
1926 – Irish Destiny, silent film
1929 – The Informer, part-talkie film
1934 – The Key, American Pre-Code film
1935 – The Informer, John Ford film
1936 – Ourselves Alone, British film
1936 – Beloved Enemy, American drama film
1937 – The Plough and the Stars, John Ford film
1959 – Shake Hands with the Devil, feature film
1975 – Days of Hope, 1916: Joining Up
1988 – The Dawning, film, based on Jennifer Johnston's The Old Jest
1989 –  The Shadow of Béalnabláth  (1989) RTÉ TV Documentary by Colm Connolly about the life and death of Michael Collins.
1991 – The Treaty
1996 – Michael Collins, feature film
1999 – The Last September (film)
2001 – Rebel Heart, BBC miniseries. The theme music of the same name was composed by Sharon Corr.
2002 –  An Deichniúr Dearmadta (The Forgotten Ten) a TG4 TV Documentary
2006 – The Wind That Shakes the Barley, feature film
2014 – A Nightingale Falling, film
2019 – Resistance, five-part RTÉ miniseries

Bibliography

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Kleinrichert, Denise Republican Internment and the Prison Ship "Argenta", 1922 (Kildare: Irish Academic Press Ltd 2000)(ISBN978-0-7165-2683-4)

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 Irish Film Institute collection of contemporary newsreels with background information


Sea slug is a common name for some marine invertebrates with varying levels of resemblance to terrestrial slugs. Most creatures known as sea slugs are actually snails, i.e. they are sea snails (marine gastropod mollusks) that over evolutionary time have seemingly lost their shells, due to having a greatly reduced or internal shell. The name "sea slug" is most often applied to nudibranchs, as well as to a paraphyletic set of other marine gastropods without obvious shells.[1]
True sea slugs have enormous variation in body shape, color, and size. Most are partially translucent.  The often bright colors of reef-dwelling species implies that these are under constant threat of predators, but the color can serve as a warning to other animals of the sea slug's toxic stinging cells or offensive taste. Like all gastropods, they have small razor-sharp teeth, called radulas. Most sea slugs have two pairs of tentacles on their head used primarily for sense of smell, with a small eye at the base of each tentacle. Many have feathery structures (cerata) on the back, often in a contrasting color, which act as gills. All species of genuine sea slugs have a selected prey animal on which they specialize for food, including certain jellyfish, bryozoans, sea anemones, and plankton as well as other species of sea slugs.[2][3]
Shell-less marine gastropods
The name "sea slug" is often applied to numerous different evolutionary lineages of marine gastropod molluscs or sea snails, specifically those gastropods that are either not conchiferous (shell-bearing) or appear not to be.[4] In evolutionary terms, losing the shell altogether, having a small internal shell, or having a shell so small that the soft parts of the animal cannot retract into it, are all features that have evolved many times independently within the class Gastropoda, on land and in the sea; these features often cause a gastropod to end up labeled with the common name "slug".

Nudibranchs (clade Nudibranchia) are a large group of marine gastropods which have no shell at all. These may be the most familiar sort of sea slug, at least to scuba divers; nudibranchs, although most are not large, are often very eye-catching because so many of species have brilliant coloration. In addition to nudibranchs, a number of other taxa of marine gastropods (some easily mistaken for nudibranchs) are also often called "sea slugs".[5]
Gastropod groups
Within the various groups of gastropods that are called "sea slugs" numerous families are within the informal taxonomic group Opisthobranchia:
The phrase "sea slug" is perhaps most often applied to nudibranchs, many of which are brightly patterned and conspicuously ornate.
For two examples see the images of Nembrotha aurea and Glossodoris atromarginata within this article.
The name "sea slug" is also often applied to the sacoglossans (clade Sacoglossa), the so-called sap-sucking or solar-powered sea slugs; these are frequently some shade of green.

Another group of main gastropods that are often labeled as "sea slugs" are the various families of headshield slugs and bubble snails within the clade Cephalaspidea.

The sea hares, clade Aplysiomorpha, have a small, flat, proteinaceous internal shell.
The clades Thecosomata and Gymnosomata are small pelagic gastropods known as "sea butterflies" and "sea angels". Many species of sea butterflies retain their shells. These are commonly known as "pteropods" but are also sometimes called sea slugs; especially the Gymnosomata, which have no shell as adults.
There is also one group of "sea slugs" within the informal group Pulmonata:

One very unusual group of marine gastropods that are shell-less are the pulmonate (air-breathing) species in the family Onchidiidae, within the clade Systellommatophora.[6]
Diversity in sea slugs
Like many nudibranchs, Glaucus atlanticus can store and use stinging cells from its prey (Portuguese man o' war) in its finger-like cerata.
Other species like the Pyjama slug Chromodoris quadricolor may use their striking colors to advertise their foul chemical taste.
The Lettuce Sea Slug (Elysia crispata) has lettuce-like ruffles that line its body. This slug, like other Sacoglossa uses kleptoplasty, a process in which the slug absorbs chloroplasts from the algae it eats, and uses "stolen" cells to photosynthesize sugars. The ruffles of the lettuce sea slug increase the slug's surface area, allowing the cells to absorb more light.
Headshield slugs like the Chelidonura varians use their shovel shaped heads to dig into the sand, where they spend most of their time. The shield also protects sand from entering the mantle during burrowing.
The largest species of sea hare, the California black sea hare, Aplysia vaccaria can reach a length of 75 centimetres (30 in) and a weight of 14 kilograms (31 lb). Most sea hares have several defenses; in addition to being naturally toxic, they can eject a foul ink or secrete a viscous slime to deter predators.