Created in 1969 as a mainly Marxist splinter group of the Irish Republican Army, PIRA was organized on four commands: one based in Dublin and the other three brigades in Northern Ireland in Londonderry, Belfast, and South Armagh. Controlled by an Army Council, PIRA later spawned a Trotskyite faction, the Irish National Liberation Army, which self-destructed following internecine warfare in 1987.
Although estimated to have an active membership of less than 500, mainly drawn from Ulster’s most economically and socially deprived areas, PIRA obtained weapons and explosives from abroad—either from sympathizers in the United States or from the Libyan revolutionary leader Col. Muammar Qaddafi—and succeeded in tying down a third of the British Army for 32 years by engaging in acts of terrorism. Comprehensively penetrated by MI5 and successive British Army intelligence and surveillance units, its political wing, Sinn Féin, entered a peace process in 1988, leaving just a small core of rejectionists, who later broke away in 1997 to form Continuity IRA and the Real IRA, but both organizations were penetrated and
suppressed following a bomb atrocity committed in Omagh in 1998.