The Real IRA emerged as one of the most dangerous groups opposed to the Good Friday agreement.
The organisation is reportedly led by the man who resigned as the Provisional IRA's 'quartermaster-general' in October 1997 after he broke with Sinn Fein because of its support for the peace process.
It is believed to be responsible for a series of large scale attacks, including a 500lb car bomb which devastated the market town of Banbridge, Co Armagh in August 1998.
The Real IRA also carried out the Omagh bombing in 15 August 1998 in which 29 people died after apparently being driven towards the bomb by misleading warnings.
The group apologised and called a ceasefire shortly after the atrocity, but began a fresh bombing campaign on the British mainland in 2001, targeting Ealing, Birmingham and BBC Television Centre in White City, London.
The 32-County Sovereignty Movement is a group of dissident republicans believed to be closely related to the Real IRA.