The Ulster Freedom Fighters has been used as a cover name for the Ulster Defence Association, though both organisations are now outlawed.
Formed in 1971, the UDA was an umbrella organisation for loyalist groups and had thousands of members at its peak. Although most killings were claimed by the UFF, the UDA was banned in 1992 for being primarily engaged in terrorism.
The UFF has been on ceasefire since 1994 and is pro-talks and pro-Agreement.
The ceasefire was breached in January 1998, when the UFF carried out three killings following the murder of loyalist leader Billy Wright in the Maze Prison. Because the UFF is linked to the Ulster Democratic Party, the UDP was suspended from the peace process for a time.
Since then, its ceasefire has remained intact. UFF prisoners are eligible for early release and some have been released.