Irish Republican Army (1922–1969)

The Irish Republican Army (IRA; Irish: Óglaigh na hÉireann, lit.'warriors of Ireland') was an Irish republican paramilitary organisation that carried on a number of violent campaigns between 1922 and 1969, in pursuit of a 32-county Irish republic. It arose from a split in the original IRA over the signing of the Anglo-Irish Treaty in December 1921, and was known during the ensuing Civil War as the Anti-Treaty IRA or the "Irregulars". It split in 1969 into the Provisional IRA and Official IRA.

The Civil War ended with anti-Treaty forces dumping arms, and over the following years, membership fell to fewer than 2,000. The IRA moved to the left in the early 1930s, under the leadership of Moss Twomey and later Seán MacBride. It swung to the right from 1938 under the leadership of Seán Russell; it had contact with the Abwehr, and Russell travelled to Nazi Germany, dying suddenly on the journey back to Ireland. From 1939 the IRA carried on the S-Plan, a bombing campaign in Britain which included the 1939 Coventry bombing, for which Peter Barnes and James McCormick were hanged. It also carried on the Northern campaign, a series of attacks on security forces in Northern Ireland. Internment without trial was introduced both in Northern Ireland and in the south, and IRA numbers were greatly reduced by the end of World War II. From 1958 to 1962 another series of attacks, called the Border campaign, were carried out, and again internment was introduced north and south.

The IRA moved to the left again in the 1960s, under the leadership of Cathal Goulding. It adopted a Marxist philosophy and advocated class-based, rather than sectarian, action. In 1969 it proposed to end abstentionism, allowing elected Sinn Féin members to take their seats in Dáil Éireann and the Northern Ireland Parliament. This, and the perceived failure of the IRA to protect Catholics during the 1969 Northern Ireland riots, led to the split at the 1969 IRA convention that resulted in the Official and Provisional IRA.