Irish Republican Army (1922–1969)

The Irish Republican Army (IRA) of 1922–1969 was a sub-group of the original pre-1922 Irish Republican Army, characterised as the Anti-Treaty IRA for its opposition to the Anglo-Irish Treaty. It existed in various forms until 1969, when the IRA split again into the Provisional IRA and Official IRA.

The original Irish Republican Army fought a guerrilla war against British rule in Ireland in the Irish War of Independence between 1919 and 1921. The Anglo-Irish Treaty signed on 6 December 1921 ended this war by granting most of the island a great degree of independence, but with six counties in the north staying within the United Kingdom as the new jurisdiction of Northern Ireland. The IRA units in the other 26 counties (that were to become the Irish Free State) split between supporters and opponents of the Treaty. The anti-Treatyites, sometimes referred to by Free State forces as "Irregulars",^A continued to use the name "Irish Republican Army" (IRA) or in Irish Óglaigh na hÉireann, as did the organisation in Northern Ireland, which originally supported the pro-Treaty side (if not the Treaty). Óglaigh na hÉireann was also adopted as the name of the pro-Treaty National Army, and it remains the official legal title of the Irish Defence Forces.