Official IRA in the context of "Provisional Irish Republican Army"

The Provisional Irish Republican Army (Provisional IRA), officially known as the Irish Republican Army (IRA; Irish: Óglaigh na hÉireann) and informally known as the Provos, was an Irish republican paramilitary force that sought to end British rule in Northern Ireland, facilitate Irish reunification and bring about an independent republic encompassing all of Ireland. It was the most active republican paramilitary group during the Troubles. It argued that the all-island Irish Republic continued to exist, and it saw itself as that state's army, the sole legitimate successor to the original IRA from the Irish War of Independence. It was designated a terrorist organisation in the United Kingdom and an unlawful organisation in the Republic of Ireland, both of whose authority it rejected.

The Provisional IRA emerged in December 1969, due to a split within the previous incarnation of the IRA and the broader Irish republican movement. It was initially the minority faction in the split compared to the Official IRA but became the dominant faction by 1972. The Troubles had begun shortly before when a largely Catholic, nonviolent civil rights campaign was met with violence from both Ulster loyalists and the Royal Ulster Constabulary (RUC), culminating in the August 1969 riots and deployment of British soldiers. The IRA initially focused on defence of Catholic areas, but it began an offensive campaign in 1970 that was aided by external sources, including Irish diaspora communities within the Anglosphere, and the Palestine Liberation Organization and Libyan leader Muammar Gaddafi. It used guerrilla tactics against the British Army and RUC in both rural and urban areas, and carried out a bombing campaign in Northern Ireland and England against military, political and economic targets, and British military targets in mainland Europe. They also targeted civilian contractors to the British security forces. The IRA's armed campaign, primarily in Northern Ireland but also in England and mainland Europe, killed over 1,700 people, including roughly 1,000 members of the British security forces and 500–644 civilians.

The republican movement refers to the Irish Republican Army (IRA) and other political, social and paramilitary organisations and movements associated with it. It can refer to:

• Republican Movement, which consisted of the IRA and Sinn Féin prior to 1969.

• Provisional Republican Movement or simply Republican Movement, which consisted of the Provisional IRA, Provisional Sinn Féin and other associated organisations.

• Official Republican Movement, which consisted of the Official IRA, Official Sinn Féin and other associated organisations.

• Irish Republican Socialist Movement, which consists of the Irish National Liberation Army and the Irish Republican Socialist Party.

• Dissident Republican Movement, which includes the Continuity IRA, Republican Sinn Féin, the Real IRA and 32 County Sovereignty Movement.

The Dissident Republican Movement itself consists of multiple movements: