Defining the "Irish Republican Army", or in short IRA, is not as easy as it seems. The public perception of the IRA, as well as self-serving propaganda, usually refers to many different entities and organizations which are all included under this convenient blanket term. Grouping all of these entities together tends to make defining the IRA much more difficult. However, this is unlikely to change in the future as new "IRA" splinter groups appear with alarming regularity, claiming the one, true title for its activities.
Here is a short run-down of organizations called the "Irish Republican Army", and what the name does and does not mean.
Irish Republican Army - 1866 to 1870
Just after the War Between the States, in the years between 1866 and 1870, the US-based Fenian Brotherhood instigated and carried out what is known as the "Fenian Raids". These were ultimately unsuccessful attacks on British army forts and customs posts in Canada. They were started in the hope of putting pressure on Britain to withdraw from Ireland. The actual raids were carried out by a rag-tag assortment of Fenians, some apparently wearing a uniform of green (and otherwise very similar to uniforms of the Union army) - buttons of which were showing the abbreviation "I.R.A." for Irish Republican Army. Also flags with the IRA name seem to have been carried (or at least designed).
Irish Republican Army - 1916 to the 1920s
The term "Irish Republican Army" (or at least versions of the same name) came into use during the Easter Rising of 1916 when the combined forces of the Irish Volunteers and the Irish Citizen Army tried to overthrow British rule in Ireland. After their defeat, the remnants of the rebel forces re-organized and from 1918 regularly referred to themselves as the Irish Republican Army. In this case, the IRA referred to the armed forces of Ireland as an emerging nation-state. From 1919 to 1921 this Irish Republican Army fought against British forces in a guerilla war, the Anglo-Irish War or Irish War of Independence. When this ended with the Treaty, parts of the Irish Republican Army became the regular armed forces of the Free State, while those disagreeing with the partition formed the anti-Treaty Irish Republican Army. Confusingly, this version of the IRA fought against Free State forces. Even after defeat, many in the Irish Republican Army claimed that they, and not the Dail Eireann, represented the true government of Ireland.
Irish Republican Army - Post-Civil War until the 1960s
The Irish Republican Army continued as an underground organization after the defeat in the Irish Civil War and was still actively preparing for armed insurrection. Occasional raids, bombings, and shoot-outs happened, both in Ireland and abroad. While continuing to claim legitimacy both as the "true government" and as the successor of the Irish Republic as declared in 1916, the Irish Republican Army in reality became a hotch-potch of ideas, ideologies and idealists. Changing course now and then and veering from Communist sympathies to collaboration with Nazi Germany (all defended by an early "by any means necessary" doctrine that classified every enemy of Britain as a possible ally). The "Border Campaign" during the 1950s and early 1960s was the last large-scale military engagement of this version of the Irish Republican Army.
1960s Split - Official IRA and Provisional IRA
In the 1960s, the leadership of the Irish Republican Army began to seek alliances (again) with Communist and Socialist ideas, scrapping the doctrine of aiding just the Nationalist side and instead opting for an all-out proletarian revolution. This revolution failed to materialize, mainly due to sectarianism in Northern Ireland. In 1969, the fractions split.
The Official Irish Republican Army continued to fight against British forces until 1972 and then announced a conditional ceasefire. Since then it has mainly made headlines by broad political statements, internal feuding with other Republicans and a possible involvement in organized crime. It was only disarmed in 2010.
The Provisional Irish Republican Army, also known as PIRA or "Provos", carried out most armed attacks in the coming years and built a strong political base through Sinn Fein. While primarily engaged in fighting British forces, the PIRA was also involved in "side activities" that could be seen as involvement in organized crime and vigilantism. With the rise of the political profile of the Sinn Fein party, the PIRA became a liability and was convinced to agree to a ceasefire in 1997, leading to the Good Friday Agreement. In July 2005 the Provisional Irish Republican Army announced the end of its military campaign and decommissioned all arms.
Another splinter group was the Irish National Liberation Army.
Dissidents - CIRA and RIRA
With both the Official and Provisional Irish Republican Army slowly veering from bullet to ballot, hardliners were (as expected) disappointed and began to split away from the old order. Several groups were formed - often it is not quite clear whether these are separate entities, where there are overlaps and what the actual aim of the group is. What these groups seem to share is an often poorly defined ideological claim to a "Free United Ireland".
Two major dissident groups claim the name Irish Republican Army and thus legitimacy:
- The Continuity Irish Republican Army (Continuity IRA or CIRA) was created as a splinter group of the Provisional IRA in 1986, but it did not operate actively until the PIRA ceasefire of 1994. The CIRA is still armed and active, its strength and arsenal are unknown. In the true spirit of Republicanism, the CIRA created several splinter groups that also claim to be the one, true IRA.
- The Real Irish Republican Army (Real IRA or RIRA) is another splinter group that broke away from the Provisional IRA, this time in 1997 following the ceasefire declaration. The RIRA is the largest and most active of the dissident factions. It was responsible for the massacre at Omagh in 1998.