The IRA formally ordered an end to its armed campaign and vowed to bring an end to more than 30 years of violence as it called on all its members to stand down from 4pm on July 28, 2005.

The republican organisation's decision to pursue its objectives through politics and "exclusively peaceful means" came in the wake of a general election which featured a strong showing by both Sinn Fein and the Democratic Unionist Party (DUP).

Sinn Fein President Gerry Adams said the "courageous and confident initiative" was a "defining point in the search for a lasting peace with justice".

Sinn Fein president Gerry Adams speaks to the media in party headquarters, West Belfast, where he urged loyalist paramilitaries to follow the IRA and ditch their guns.

Prime Minister Tony Blair, fresh from securing a third term in office, billed the announcement as a "step of unparalleled magnitude".

Others weren't so easily convinced.

DUP leader Ian Paisley warned that the IRA had a history of "reverted to type", saying "we will judge their bona fides over the next months and years based on its behaviour and activity".

The scepticism of Paisley and his fellow Unionists was understandable.

[Read more: January 30, 1972 - 13 die on Bloody Sunday as Derry protest turns to massacre]

Decommissioning had been a central plank of the Good Friday Agreement of 1988 but it had hit several significant bumps along the way, not least the IRA's alleged involvement in a robbery of £26.5m from Northern Bank in December 2004 and the murder of Belfast man Robert McCartney in January 2005.

But something was different about the IRA's latest announcement. Al-Qaeda had stripped any remaining vestiges of 'just war' from terrorism, and the IRA's voluntary ceasefire formed a conscious - if unspoken - rejection of the murderous tactics employed by Islamic extremists in the heart of London just 20 days previously.

Perhaps more significantly still, a former IRA prisoner was chosen to read the statement to camera. In doing so, Seanna Breathnach became the first IRA member since 1972 to represent the organisation without wearing a mask. His identity would also prove crucial: he had been a friend and cellmate of Bobby Sands, the first of the IRA hunger strikers to die.

John de Chastelain, the retired Canadian general who has been responsible for overseeing the decommissioning process since 1997, was duly invited to complete his work alongside two religious witnesses - Rev Harold Good, a former president of the Methodist Church in Ireland, and the Rev Alex Reid, a Catholic priest (below).

Protestant Minister Rev Harold Good (left) with Catholic Priest Father Alex Reid would act as independent witnesses to the decommissioning.

On September 26, De Chastelain announced that the IRA's last remaining weapons had been "put beyond use", declaring himself "satisfied that the arms decommissioned represent the totality of the IRA's arsenal".

To general applause from both sides of Northern Ireland's great divide, he added: "This can be the end of the use of the gun in Irish politics."

But the DUP again sounded a note of caution, claiming that there had been no transparent verification of decommissioning, and that the church witnesses had been selected by the IRA and as such could not be considered 'independent'.

More damningly, no provision was made for dissident factions of the IRA who remained steadfastly opposed to the power-sharing settlement in Belfast.

The Real IRA, the biggest and most active of these splinter groups, went on to claim responsibility for the 2009 attack on the Massereene Barracks that killed two British soldiers, the first to be killed in Northern Ireland since 1997.