The dirty protest was part of a five-year protest during the Troubles by Provisional Irish Republican Army and Irish National Liberation Army prisoners held in the Maze Prison and a protest at Armagh Women's Prison in Northern Ireland.

What is a dirty process?

A dirty protest is where a prisoner has chosen to defecate or urinate in a cell without using the facilities provided. Blood or other body fluids may also be present. In the majority of cases the walls, floor or ceiling are affected.

Why did the blanket protest happen?

At the end of April 1978 a fight occurred between a prisoner and a prison officer in H-Block 6. ... This resulted in the blanket protest escalating into the dirty protest, as the prisoners were unable to "slop out" (i.e., empty their chamber pots) so resorted to smearing excrement on the walls of their cells.