Republican paramilitary organization, founded in 1919, seeking the end of British rule in Northern Ireland and the unification of the province with the republic of Ireland.
The IRA used armed force to achieve the same objectives as Sinn Féin , though the two always operated independently. After the establishment of the Irish Free State (1922), the IRA refused to accept a separate Northern Ireland , and the violence continued. The IRA was declared illegal in 1931, and the Irish legislature provided for internment without trial for its members. It gained popular support in the 1960s when Catholics in Northern Ireland began a civil rights campaign against discrimination by the dominant Protestant majority. In 1969 the IRA split into the Marxist Official wing, which eschewed violence, and the Provisionals (Provos), Ulster Catholics committed to the use of terror tactics against Ulster Protestants and the British military, tactics that included the 1979 assassination of Lord Mountbatten and the killing of more than 3,000 people. In 1994 the IRA declared a cease-fire, and its political representatives were included in multiparty talks beginning in 1997. Negotiations produced the Good Friday Agreement, in which the IRA agreed to decommission its weapons (disarm). In 2000 the IRA agreed to allow international inspections of its weapons as a first step in the process of putting them "beyond use," though it continued to resist decommissioning.