1916
The Irish Republican Brotherhood stages a terrorist campaign against Britain on Easter Monday. It is limited to Dublin and fails. The leaders are executed.

1918
Remnants of terrorist units from the Easter terrorist campaign form the IRA. It was organized by Michael Collins and was composed of the more militant members of the Irish Volunteers, a paramilitary organization established by Irish Nationalists in 1913 to secure independence for Ireland. The IRA becomes the military wing of the Sinn Fein party.

1922
The Irish Free State is formed. It includes 26 of the 32 counties on the island of Ireland. It remains a dominion under the British Crown. The IRA becomes a stronghold of opposition to the Irish Free State’s dominion status and to a separate Northern Ireland. The IRA is responsible for numerous bombings, raids, and street battles on both sides of the Irish border in the early years of the Free State.

In August, Collins is assassinated. He had been a senior member of the Free State government.

1932
Eamon De Valera, one of the IRA’s founders, becomes head of the Irish Free State government when his party wins the election. Support for the IRA begins to decline due to internal dissension and continued violence. The organization also loses credibility during the Second World War for its pro-German stance.

1949
The IRA’s decline picks up speed as the Irish Free State cuts all ties to Britain by becoming the Republic of Ireland. The government tries to crack down on IRA violence. Eventually, the organization is made illegal on both sides of the border.

1956-57
The IRA briefly escalates a bombing campaign in Belfast, London and in border areas between the Republic of Ireland and Northern Ireland. Its activities wane considerably for more than 10 years.

1969
The Catholic population in Northern Ireland had grown rapidly in the years following the Second World War, much of it as a result of immigration from the repubilc. Tension rises as Catholics demand an end to discrimination at the hands of Protestants. Protests erupt into violence.

The IRA splits into two factions. The “Officials” call for a united socialist Ireland but turn their backs on a campaign of violence to achieve it. The “Provisionals” claim armed attacks are necessary to achieve unification. The Provisionals begin a systematic campaign in Northern Ireland.

British troops are sent in to Northern Ireland.

1971
On Aug. 9, the Northern Ireland government extends police powers to allow jailing of people without trial in an attempt to end the escalating violence. Security forces try to arrest 400 republicans – but most escape. Of the 100 who are arrested, most are released within days. As the numbers of those interned increase over the next few months, so does anger in the Catholic community. Support for the IRA continues to grow among Catholics.

Jan. 30, 1972
British troops open fire on Catholic demonstrators protesting against the internment law. Thirteen civilians are killed. A fourteenth dies later in hospital. Britain maintained that the troops opened fire only after they were attacked.
36 years after Bloody Sunday it is still highly contentious what exactly happened on that day. The events are now subject to a fresh inquiry chaired by Lord Saville of Newdigate and has cost the British Tax payers £182m so far.

Support for the Provisional IRA continues to increase. The Provisionals take their bombing campaign to England.

The Official IRA calls an indefinite ceasefire.

Nov. 14, 1973
Six men and two women are convicted of setting off two car bombs in London. One person died and almost 200 were injured in the attacks. One bomb blew up outside the Old Bailey criminal court, while the other went off outside Scotland Yard. All eight were said to be members of the Provisional IRA. They’re handed life sentences and almost immediately begin hunger strikes, demanding to be transferred to prisons in Ireland. One of the convicted men – Gerry Kelly – eventually serves on the Sinn Fein delegation that negotiated the Good Friday Agreement.

April 20, 1974
Jerry Murphy, a Roman Catholic, becomes the 1,000th person to die in the violence that erupted since 1969.

May 17, 1974
Thirty-three people die when bombs go off in Dublin and Monaghan. Twenty years later, the Ulster Volunteer Force, a Protestant paramilitary organization, admits it carried out the attack.

June 17, 1974
A bomb goes off at the Houses of Parliament in London, injuring 11 people. The IRA claims responsibility.

July 17, 1974
A bomb goes off at the Tower of London, killing one person and injuring 41. No one was arrested and no group ever claimed responsibility.

Nov. 21, 1974
Bombs rip through two pubs in Birmingham, killing 21 people. The blasts occur 12 minutes after someone “with an Irish accent” called in a warning to a local newspaper. Six people are eventually convicted of the attack, but they are released after serving 16 years when their convictions are overturned. Thirty years after the attack, Sinn Fein said the attacks should never have happened and indicated an apology was imminent.

Nov. 27, 1975
IRA gunmen kill Guinness Book of Records co-founder and editor Ross McWhirter outside his North London home. McWhirter had been an outspoken critic of the IRA.

Aug. 27, 1979
An IRA bomb kills the Queen’s cousin, Lord Louis Mountbatten and several others on his yacht in Ireland. A few hours later, 18 British soldiers are killed in two booby-trap bomb explosions near Warrenpoint close to the border with the Irish Republic. The IRA claims responsibility for that attack as well and issues a statement which says: "This operation is one of the discriminate ways we can bring to the attention of the English people the continuing occupation of our country."

May 5, 1981
Bobby Sands becomes the first of 10 IRA prisoners to commit suicide while on hunger strikes. Shortly after the beginning of the strike in March, the independent republican MP for Fermanagh & South Tyrone died, which led to a by election. Sands was nominated as a candidate, and won the seat on April 9, 1981. Three weeks later, he died from starvation in the prison hospital. The announcement of his death led to several days of rioting in Northern Ireland.

1983
Gerry Adams wins the leadership of Sinn Fein.

Oct. 12, 1984
The IRA targets the British government as it detonates a bomb at a hotel in Brighton, where the Conservative cabinet of Prime Minister Margaret Thatcher was meeting. Five people are killed – including an MP. The bomb had been planted several weeks earlier by Patrick Magee, who was sentenced to 35 years in prison for the attack. He was released in 1999 under provisions of the Good Friday Agreement.

Nov. 8, 1987
An IRA bomb kills 11 civilians at a Remembrance Day service in Enniskillen. It is the highest death toll in an attack in Northern Ireland in five years. The IRA expresses its "deep regret" while Sinn Fein Leader Gerry Adams criticizes the bombing for undermining the "legitimate" use of physical force. Support for the IRA around the world plunges.

Meanwhile, the British elite SAS continues to target IRA members, shooting dead three unarmed IRA members in Gibraltar.

Sept. 22, 1989
A bomb blows apart the recreation centre at the Royal Marine School of Music in Deal, killing 11 soldiers. The IRA claims responsibility.

Aug. 31, 1994
The IRA declares a “complete cessation of military operations.” The move came months after U.S. President Bill Clinton enraged London by granting Sinn Fein Leader Gerry Adams a visa to visit the United States.

Adams told his supporters that this was the clearest sign yet that the political process was working.

Six weeks after the IRA’s declaration, the two main loyalist groups joined in the ceasefire.

Feb. 10, 1996
The ceasefire is shattered when the IRA bombs the Docklands area of London. Two people are killed.

Feb. 18, 1996
A bomb rips apart a London bus. One person is killed – the IRA bomber who was carrying the device. It exploded prematurely.

July, 1997 The IRA announces another ceasefire. Following that move, Sinn Fein is invited to take part in talks aimed at creating a new Northern Ireland Assembly comprised of Protestants and Catholics, which would lead to greater co-operation between Northern Ireland and the Irish Republic.