The blanket protest was part of a five-year protest during the Troubles by Provisional Irish Republican Army (IRA) and Irish National Liberation Army (INLA) prisoners held in the Maze prison (also known as "Long Kesh") in Northern Ireland. The republican prisoners' status as political prisoners, known as Special Category Status, had begun to be phased out in 1976. Among other things, this meant that they would now be required to wear prison uniforms like ordinary convicts. The prisoners refused to accept that they had been administratively designated as ordinary criminals, and refused to wear the prison uniform.
Convicted paramilitary prisoners were treated as ordinary criminals until July 1972, when Special Category Status was introduced following a hunger strike by 40 IRA prisoners led by the veteran republican Billy McKee. Special Category, or political, status meant prisoners were treated very like prisoners of war, for example, they did not have to wear prison uniforms or do prison work. In 1976, as part of the policy of "criminalisation", the British Government brought an end to Special Category Status for paramilitary prisoners in Northern Ireland. The policy was not introduced for existing prisoners, but for those convicted after 1 March 1976.
The end to Special Category Status was a serious threat to the authority which the paramilitary leaderships inside prison had been able to exercise over their own men, as well as being a propaganda blow. The imminent withdrawal of Special Category Status caused relations between the prisoners and prison officers to deteriorate, and in early 1976 the IRA leaders in prison sent word to the IRA Army Council asking them to begin assassinating prison officers, stating "we are prepared to die for political status. Those who try to take it away from us must be fully prepared to pay the same price". Outside the prison the IRA responded by shooting prison officer Patrick Dillon in April 1976, the first of nineteen prison officers to be killed during the five-year protest.