The New IRA was established in 2012 when members of the Real IRA, Republican Action Against Drugs and a number of independent republicans came together.
The formal admission by the group on Tuesday that it killed Derry-based journalist Lyra McKee caused no surprise, even if its defence of its action infuriated many.
It is the most dangerous of the dissident republican groups, made up of young inexperienced members and those old enough to have been involved in violence during the days of the Provisional IRA.
While just seven years old it had blood on its hands long before the Creggan shot, being responsible for numerous gun and bomb attacks and the murders of two prison officers in the North.
David Black (52) was shot dead as he drove to work in Maghaberry Prison in Co Armagh in 2012, while Adrian Ismay died 11 days after a bomb exploded under his van in Belfast in 2016.
The New IRA also wields a degree of control in republican areas, and has carried out many so-called “punishment” attacks.
In 2016 taxi driver Michael McGibbon (33) died after he was shot three times in the leg in such an incident in Ardoyne, north Belfast. He bled to death after one of the shots severed an artery.
In advance of the formation of the New IRA some of its members are believed to have been involved in the 2011 murder of PSNI officer Ronan Kerr in Omagh, and two years earlier in Antrim in the murders of British soldiers Patrick Azimkar and Mark Quinsey.
It has also targeted many more PSNI officers with gun and attempted under-car booby trap bomb attacks. A number of police officers have been forced to move home as a result of such incidents.
In January 2017 it wounded a police officer aged in his 20s when it fired up to 10 shots from an automatic weapon at a filling station on the Crumlin Road in north Belfast.
Given the danger that attack posed to the wider community, just like as happened in the Creggan, PSNI chief constable George Hamilton called it "crazy" and "completely reckless".
In January it carried out a car bomb attack outside the courthouse in Derry. The New IRA also said it was responsible for sending parcel bombs to London and Glasgow last month.
Security sources say that it has a store of the high explosive Semtex that they believe was “siphoned off” from old Provisional IRA stock.
Since the killing of Lyra McKee, Saoradh has come into public focus in a way it did not do so before, particularly in the wake of Easter commemoration marches in Cork and Dublin.
It says it is a standalone political organisation, but it is viewed as reflecting the views of the New IRA, a connection it did little deny with the paramilitary trappings on view in O’Connell Street in Dublin on Saturday.
In recent years the New IRA superseded Oglaigh na hÉireann as the most lethal of the dissident organisations. The latter was involved in many gun and bomb attacks, but it is believed not to have claimed lives.
It carried out a car bomb attack that severely injured PSNI officer Peadar Heffron in 2010, and the same year was behind the car bomb attack on the British army's Palace Barracks in Hollywood, Co Down, which houses MI5's headquarters in Northern Ireland.
In 2009 it was involved in a failed 400lb car bomb attack on the headquarters of the North’s Policing Board in Belfast.
Its effectiveness was severely curtailed when its leader and long-standing republican Seamus McGrane was arrested in 2015, three years later receiving an 11½-year prison sentence at the Dublin Special Criminal Court for directing terrorism.
Oglaigh na hÉireann
In January last year Oglaigh na hÉireann said it was suspending “all armed actions against the British state” with immediate effect.
Oglaigh na hÉireann was itself a splinter from the Real IRA which was involved in the 1998 Omagh bombing which killed 29 people including a woman heavily pregnant with twin girls. While still said to be in existence, its effectiveness and level of threat is seen as now limited.
The oldest of the modern-day splinter republican paramilitary groups is the Continuity IRA, which was formed in 1986 following a split with the Provisional IRA. While dangerous in its early years, it is now viewed as weakened and heavily infiltrated.