This is a timeline of actions by the Official Irish Republican Army (Official IRA or OIRA), an Irish republican & Marxist-Leninist paramilitary group. Most of these actions took place as part of a Guerrilla campaign against the British Army & Royal Ulster Constabulary and internal Irish Republican feuds with the Provisional IRA & Irish National Liberation Army from the early 1970s - to the mid 1970s during the most violent phase of "the Troubles" in Northern Ireland.