WHO: Ruled by a seven-man council and 11-member executive. Current membership estimated at 500 to 1,000.

DEATH TOLL: Killed 1,775 people from 1970 to 2005, maimed several thousand more in shootings and explosions, and devastated scores of towns and cities in Northern Ireland and England with vehicle bombs and firebombs.

HUMAN TARGETS: The IRA killed 638 members of British security forces, chiefly the army; 640 civilians, most of them Protestants; 273 police officers in Northern Ireland, six in the Irish Republic and five in England; 149 of its own members, either accidentally in explosions or deliberately as suspected traitors; 28 members of outlawed Protestant paramilitary groups; 23 prison officers; 12 members of rival anti-British paramilitary groups and one Irish soldier.

NOTEWORTHY ATTACKS:

Aug. 12, 1970, IRA kills first two Northern Ireland police officers, using a booby-trapped bomb hidden in an abandoned car in South Armagh, a border region that became known as the IRA's "bandit country."

Feb. 6, 1971, IRA kills first British soldier in a sniper attack in north Belfast.

July 21, 1972, "Bloody Friday," when 20 bombs detonate in Belfast within an hour, killing nine people and wounding 130.

Nov. 21, 1974, two bombs devastate pubs in Birmingham, England, killing 21 and wounding 160 — the IRA's worst toll of bloodshed in a single attack.

Jan. 5, 1976, the Kingsmills massacre, when the IRA shoots to death 10 Protestant civilians at a roadside after stopping their bus.

Feb. 17, 1978, IRA firebomb burns to death 12 Protestants in a suburban Belfast hotel.

Aug. 27, 1979, IRA blows up Lord Louis Mountbatten, a cousin of     Queen Elizabeth II, and three others on his private boat in the Irish Republic. On the same day the IRA kills 19 members of the British army's elite Parachute Regiment with two remote-controlled roadside bombs.

Oct. 12, 1984, IRA bombs hotel on south English coast hosting the annual party of Britain's ruling Conservative Party, narrowly missing Prime Minister Margaret Thatcher but killing five others, including a lawmaker.

Nov. 11, 1987, IRA kills 11 Protestants in a bombing in Enniskillen during a memorial service for World War I and II dead.

Jan. 17, 1992, IRA kills eight Protestant construction workers with a remote-controlled roadside bomb at Teebane crossroads.

Oct. 23, 1993, IRA kills nine Protestant civilians, including two children, and one of its own members in a botched bombing on Shankill Road, a hard-line Protestant district of Belfast.

Feb. 12, 1997, IRA kills 23-year-old British soldier Lance Cpl. Stephen Restorick, who was shot in the back in a long-range sniping attack in South Armagh — the IRA's last killing of a British soldier.

June 16, 1997, IRA kills two Protestant police officers, shooting them in the back of the head at close range in the town of Lurgan. IRA calls a cease-fire 34 days later.