Soloheadbeg ambush in the context of "Irish Volunteers"

The Irish War of Independence (Irish: Cogadh na Saoirse), also known as the 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 part of the Irish revolutionary period.

In April 1916, Irish republicans launched the Easter Rising against British rule and proclaimed an Irish Republic. Although it was defeated after a week of fighting, the Rising and the British response led to greater popular support for Irish independence. In the December 1918 election, 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 killed in the Soloheadbeg ambush by IRA volunteers acting on their own initiative. The conflict developed gradually. For most 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 throughout Ireland, Sinn Féin was proclaimed (outlawed) in County Cork 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, some of which were authorised by the British government. Thus the conflict is sometimes called the "Black and Tan War". The conflict also involved civil disobedience, notably the refusal of Irish railwaymen to transport British forces or military supplies.

The First Dáil (Irish: An Chéad Dáil) was Dáil Éireann as it convened from 1919 to 1921. It was the first meeting of the unicameral parliament of the revolutionary Irish Republic. In the December 1918 election to the Parliament of the United Kingdom, the Irish republican party Sinn Féin won a landslide victory in Ireland. In line with their manifesto, its MPs refused to take their seats, and on 21 January 1919 they founded a separate parliament in Dublin called Dáil Éireann ("Assembly of Ireland"). They declared Irish independence, ratifying the Proclamation of the Irish Republic that had been issued in the 1916 Easter Rising, and adopted a provisional constitution.

Its first meeting happened on the same day as one of the first engagements of what became the Irish War of Independence. Although the Dáil had not authorised any armed action, it became a "symbol of popular resistance and a source of legitimacy for fighting men in the guerrilla war that developed".