The Irish War of Independence

irish war of independence
A World War I recruiting poster pitched at the men of Ireland

The Irish War of Independence (1919-21) was a brief but intense conflict, culminating in the creation of a free Irish state. It followed the 1916 Easter Rising, an effect a military defeat but a propaganda victory for Irish Republicans, who gained considerable support following Britain’s heavy-handed response to the uprising. The surge in Irish Republicanism is also attributed to the issue of military conscription. In early 1918 the British government, which was planning a major offensive on the Western Front, decided to extend conscription to Ireland. More than 120,000 Irishmen had volunteered to fight in World War I and British policymakers hoped to raise another 30,000 through compulsory service. The introduction of conscription in Ireland created a significant backlash from the Irish people, the Catholic clergy and various political groups. It also united Ireland’s disparate Nationalist groups. Socialists, radical Republicans and moderates set aside their political differences to form the Irish Anti-Conscription Committee. On April 23rd 1918 the Anti-Conscription Committee coordinated the largest general strike in Ireland’s history. This was followed by a series of massive anti-conscription rallies in several cities.

The rise of Sinn Fein

The political beneficiary of this tumultuous period was Sinn Fein. Previously a fringe group with unclear aims, Sinn Fein emerged from the Easter Rising and the anti-conscription campaign as a political party committed an independent Irish republic. Support for Sinn Fein grew rapidly, as Irish Republicans of various hues fell behind the party. In the British general election of December 1918, Sinn Fein won 73 seats in the House of Commons, making it the third-largest party in the British parliament. Despite this success, Sinn Fein’s leadership adopted a policy of abstention, choosing not to occupy its Westminster seats. Instead, Sinn Fein’s elected politicians gathered in Dublin’s Mansion House in January 1919. There they declared the formation of an independent Ireland and proclaiming themselves the Dail Eireann (‘Assembly of Ireland’). In April the Dail Eireann elected Eamon de Valera, a veteran of the Easter Rising, as president of this fledgeling republic. Another young Republican, Michael Collins, became its finance minister. Through the middle of 1919, Sinn Fein agents ventured abroad to international recognition and financial support for their independent government. In September 1919 London declared the Dail Eireann an illegal body, forcing it to meet less regularly and in secret locations.

irish war of independence
Sinn Fein members of the first Dail Eireann in 1919

These political developments were accompanied by an escalation in violence. On the same day the Dail Eireann convened in Dublin, several Republican agents, acting on their own initiative, shot and killed two Royal Irish Constabulary (RIC) officers in County Tipperary. Many consider this violence the starting point of the Irish War of Independence. The first iteration of the Irish Republican Army (IRA) was formed in early 1919. Its members were drawn from the Irish Volunteers, along with remnants of the Irish Citizens Army. Sinn Fein leaders in the new Republican government worked hard through 1919 to bring the IRA under its control. It was not an easy task: the IRA and its antecedent bodies had always acted independently and were not amenable to political control. Eventually, through the efforts of Michael Collins and others, the IRA came under the control of the Dail Eireann and served as its de facto military wing. Though the Sinn Fein government never formally declared war, it later asserted that a state of war existed between the new Irish Republic and Britain, due to Britain’s ongoing occupation of Ireland.

Michael Collins and guerrilla warfare

Irish War of Independence
Black and Tans search a suspect during the Irish War of Independence

The Irish War of Independence unfolded as a brutal internecine war. Its conflicts were shaped by sectarianism and retaliatory violence between the IRA, the RIC and the notorious Black and Tans (British army veterans recruited to serve in Ireland in support of the RIC). The Irish War of Independence was a guerrilla war, fought not on battlefields but in cities, towns and among civilian populations. Its fighting caused more than 2000 deaths, as well as extensive destruction and damage to infrastructure and private property. The IRA’s paramount objective was to drive the British from Ireland by making it too difficult to govern and too dangerous to occupy. IRA leader Michael Collins, a brilliant tactician, ordered raids on RIC headquarters across Ireland in order to seize weapons for his men. Once armed, small groups of IRA fighters ambushed and assassinated RIC members and British political and military targets. The IRA was significantly outnumbered by the enemy but this was offset by Collins’ use of clandestine warfare and evasive tactics. Under Collins’ direction, the IRA was organised into ‘flying columns’ that could carry out hit-and-run raids. Another specialist unit dubbed the Twelve Apostles, or simply ‘The Squad’, carried out assassinations against British intelligence agents and pro-British police.

“The Irish War of Independence was an unnecessary and often brutal little war. It was unnecessary in that the democratic wishes of the Irish people should have been adhered to… In the general election of December 1918 some 72 percent of the population of Ireland voted for independence – but democracy was again denied. When democracy fails, as it did not once but twice, all that remains is to take up arms.”
Joseph McKenna, historian

In 1920 London responded to the worsening situation in Ireland by recruiting ex-military personnel to join the RIC as special constables. These volunteer units were given three months’ training and attached to RIC stations around Ireland. The Black and Tans, so called for the non-matching uniforms they were issued in 1920, became notorious for their poor conduct and arbitrary use of violence in Ireland. Given significant authority, but lacking a firm command structure, the Black and Tans often acted independently and employed methods not sanctioned by the British government. There were reports of Black and Tans using threats, beatings and even torture when interrogating suspected Republicans. On November 21st 1920 the IRA’s ‘Twelve Apostles’ hit squad assassinated 14 British MI5 officers at various locations in Dublin. The RIC and Black and Tans retaliated with horrific violence at a Gaelic football game at Croke Park. After surrounding the ground with the intention of searching for suspected Republicans, rogue police and Black and Tans began firing indiscriminately, killing 14 people and injuring 66 others. The events of this particular day, the first of Ireland’s ‘Bloody Sundays’, is an example how the Irish War of Independence was driven by retaliatory violence.

ireland war of independence key points

1. The Irish War of Independence (1919-21) was a brief but violent conflict between British authorities and the IRA. It culminated in the Anglo-Irish Treaty and the formation of a free Irish state.

2. The war erupted in the wake of the 1916 Easter Rising, Britain’s heavy-handed response to this rebellion and the British government’s plan to introduce military conscription in Ireland.

3. The anti-conscription campaign fuelled the rise of Sinn Finn, which won 73 seats in parliament. In early 1919 Sinn Fein MPs declared an independent Ireland and formed the Dail Eireann.

4. Formed from the Irish Volunteers and other groups, the Irish Republican Army became Dail Eireann’s military wing, launching attacks on the police and British targets.

5. The Irish War of Independence culminated in the Anglo-Irish Treaty, signed in December 1921. This treaty created the Irish Free State, a self-governing British dominion. Northern Ireland was allowed to opt out of the Free State, which it immediately did. The treaty caused a split in both Sinn Fein and the IRA and led to the Irish Civil War (1922-23).

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This page was written by Rebekah Poole and Jennifer Llewellyn. To reference this page, use the following citation:
R. Poole and J. Llewellyn, “The Irish War of Independence”, Alpha History, accessed [today’s date],